I also have some other questions regarding ancient Siam/Ayutthaya:
What were the chances of Ayutthaya becoming an Asian superpower at the time?
How strong and powerful was Ayutthaya and the Ayutthayan military?
How were elephant trained to handle combat on the battlefield?
There are 3 people on a war elephant. There’s the nobleman/Prince/king/general riding on the elephant’s neck, the mahout at the back, and a guy in the howdah(?)/sear with weapons. What was the guy in the seat’s role while in battle?
Can regular soldiers ride war elephants?
How were war elephants treated by the Ayutthayan/Burmese military and Ayutthayan/Burmese society?
How common were elephant duels on the scale of King Naresuan and the Crowned Prince of Burma’s duel?
What happened to elephants who died on the battlefield?
Were there social stigmas against killing a war elephant?
Did the Ayutthayan and Burmese militaries establish a formal rank system a la modern day militaries? (I.e. private, Private First Class, sergeant, sergeant major, etc./lieutenant, captain, major, colonel, general, etc.)
Was Ayutthaya an “Asian power” during King Naresuan’s rule/at Ayutthaya’s peak?
In a hypothetical war, would Ayutthaya under King Naresuan/at Ayutthaya’s peak be able to fight the Chinese and Japanese?
The 1593 elephant duel itself is actually a subject of historical debate. It only appears in the Thai chronicles, while the Burmese chronicles state that the Uparaja (crown prince) was killed by a gunshot. The duel features heavily in traditional Thai historiography, though, and is credited as firmly establishing Ayutthaya's "independence" from Burma (which conquered it in 1569). While under current views the reality is more nuanced, the supposed elephant duel (and Naresuan's campaigns that followed) did mark an end of an era; warfare subsided afterwards (due to changes in tactics and the increased costs of war), and the geopolitics between Burma and Siam became pretty much settled for the following 150 years.
You might be interested in the article What Happened at Nong Sarai? Comparing Indigenous and European Sources for Late 16th Century Siam by Barend Jan Terwiel, which provides a broad analysis of the event.