This is a classic historiographical debate. I will attempt to answer the question to the best of my ability, but you should know (and can probably tell from my username) that I do have strong partisan feelings on one side of this debate. I'll attempt to be brief, and provide you with some avenues to explore the question yourself.

Timothy Blanning, one of the most well-known eighteenth-century historians, and author of a recent biography of Frederick the Great, summarized the problem like this 2007 book, The Pursuit of Glory: Five Revolutions that Made Modern Europe,1648-1815:

"So war had not lost its teeth. Yet taking a long view of the period 1648-1815, or at least 1648-1792, it can be seen that it did gradually lose some its destructive force. It was not that wars became less frequent: on the contrary, there was a major war between European powers in every decade of the eighteenth century except perhaps the 1720s. Rather, it was the case that armies were now better disciplined and better provisioned... one state after another moved to establish control over their armed forces. War was still a terrible affliction for anyone unfortunate to get in its way, but conflicts did become shorter in duration and more limited in geographical scope. It was Frederick the Great's declared ambition to isolate warfare from civilians to the extent that they would be unaware that it was underway. Of course, he failed, indeed, he himself claimed that the Seven Years War had been as catastrophic from a demograhic point of view as the Thirty Years War. However, there was no return to the anarchy of the first half of the seventeenth century. ... This verdict has been confirmed, albeit more prosaically by Fritz Redlich, who, in a general account of military depredation between 1500 and 1815, concluded: 'The eighteenth century experienced a fundamental change in outlook and attitude towards looting an booty.'" (Timothy Blanning, The Pursuit of Glory: Five Revolutions that Made Modern Europe,1648-1815, 56.)

John Childs was the first to seriously challenge the idea of Kabinettskriege as a more limited era of warfare, in his 1979 book, Armies and Warfare in Europe, 1648-1789. Childs argued:

“the word limitation must be employed with great circumspection; between 1648 and 1789 wars in Europe accounted for the lives of hundreds of thousands of soldiers and civilians, destroyed numerous towns and villages, damaged national economies, and devastated much of Germany, central Europe, and the Low Countries. Warfare was ‘limited’ only when it was compared with the holocaust that had gone before and the new totality of the Napoleonic Wars." ( John Childs, Armies and Warfare in Europe: 1648-1789, 2)

Franz Szabo, Erica Charters, Eve Rosenhaft, and Hannah Smith have all been persuaded by Childs "anti-Kabinettskriege" viewpoint to some extent: In his 2008 book on the Seven Years War, Szabo notes, "The Seven Years War on the European continent was costly, bitter, and sanguinary far beyond what might be imagined from the frequently expressed stereotypical image of the ‘civilized’ and ‘limited’ warfare of that century." (Franz A. J. Szabo, ,The Seven Years War in Europe: 1756-1763, 434). In the same vein, Charters, Smith, and Rosenhaft state that,

“the conduct of war after 1648 undoubtedly became more regulated but the label of ‘limited’ or ‘restrained’ fails to convey the complex range of military experiences and civilian-military relations that can be found in the period between the end of the Thirty Years War and the start of the French Revolutionary and Napoleonic Wars.” (Erica Charters, Eve Rosenhaft, and Hannah Smith, ,Civilians and War in Europe, 1618-1815, 8)

So, based upon factors such as occupation, rape, and plundering, the Kabinettskriege-era was not "limited" in any real sense, it was still quite dangerous to be in a warzone as a civilian. However, in terms of deaths, it was perhaps less dangerous than the periods to which it is directly adjacent. You can find my estimates of total and civilian deaths during this period here: Https://kabinettskriege.blogspot.com/p/estimates-of-kabinettskriege-era-war.html . Both of these estimates use the leading secondary sources available on these conflicts.

In his 1987 book, (which I tend to concur with) Christopher Duffy had this to say regarding atrocities in the era:

Most of the European wars were fought in a manner that reflected the urbanity and reasonableness of the age. On the battlefield the English and French officers in particular sought to outdo each other in demonstrations of chivalrous concern... It was to the credit of the eighteenth century, rather than other-wise, that men justified their modernation in terms of self-interest than the ostentatious virtue: 'we must be most careful to leave the peasants with enough grain not only to live,l but also to sow their ground for another harvest, particularly if we think the next campaign will be waged in the same area.' (Turpin de Crisse, 1754, I, 145). Wise commanders knew that if they treated the local people reasonably well, they would not have chase them over the landscape to obtain food or information.

Enemy armed forces, defended fortresses and public property were considered legitimate targets, but you were expected to refrain from deeds which might, 'occasion loss and harm among the enemy, but inflict no essential damage to hostile inst rests and yield not the slightest benefits for us.' (Schertel von Burtenbach, 1779, 9-10).

The eighteenth century had its share of atrocities. A number were deliberate, but the majority were the result of some kind of miscalculation rather than the consequence of a settled policy of Schrecklichkeit [horridness]. The fortified towns of Zittau, Cuestrin, and Dresden all probably burnt more fiercely than the besieging bombardiers had intended or expected. (Christopher Duffy, The Military Experience in the Age of Reason, 13).

So, in order to arrive at a definite answer to this question, we need to define Kabinettskriege carefully, and to do so, it might help to answer the following questions:

1. In terms of civilian death, how does the era from 1648-1789 compare with what came before and after it?
2. If there is a difference in the level of civilian death in this era, what trends are responsible?
3. By other standards of measurement (battlefield experience, for example) was the eighteenth century any more limited than other periods of warfare?

To answer these question for yourself, I would encourage you to start with the following sources, and I can certainly recommend more if needed:

John Childs, Armies and Warfare in Europe: 1648-1789

Erica Charters, Eve Rosenhaft, and Hannah Smith, ,Civilians and War in Europe, 1618-1815

Christopher Duffy, The Military Experience in the Age of Reason