According to something I read it is claimed that eunuchs can and did have sex despite them being forbidden from doing so by design. Based off of that are there any first hand accounts from women who had sex with eunuchs about their sexual satisfaction and performance?

Alas, while I can confirm these attitudes about sex and eunuchs were moving around in the periods they existed and are not some contemporary thing, no, there are no (known) first-person accounts from women about sex with eunuchs. There are very few cultural spaces where we have an overlap of both eunuchs and women with enough agency to create written records, let alone written records about their thoughts and feelings about sex. (Eunuchs tend to correlate with the oppression of women, I will let you do your own causation theories on that though.)

We do have one historic record of interest to you, the divorce of Mr. and Mrs. Tenducci, which shook up late 18th century Britain. They had run away together and eloped, being married illegally by a priest, and had been on the run from her parents for some time when she initiated getting the marriage annulled, because she wanted to marry someone else. This event left two interesting records, the first is "A true and genuine narrative of Mr and Mrs Tenducci", which is allegedly written by Mrs. Tenducci herself. But despite its promise of being both true and genuine, is of disputed authorship, and we can't actually pledge Mrs. Tenducci wrote this. While there is nothing spicy here, it presents an interesting story: Dorothea (or her ghostwriter) paints herself very much as the aggressor to this marriage, pleads for tolerance, and makes pretty casual mention of them sharing a bedroom, waking up together, dressing together, in short the usual non-sexual intimacies married people enjoy. I think we can infer plenty from this myself... So this primary source is not quite what you're looking for, but it's sideways to it, and you should read it anyway, it's short. The court records for this divorce are also available on Google Books to look through, they contain more graphic discussion of Tenducci's physical state. You will note, however, that most of this record focuses on procreation and not sex per se. Sex, as it were, isn't the point here, it's about whether or not the marriage was valid, and without procreation, it was not. You may find this old comment of mine on the sexuality and non-procreation of eunuchs interesting. The Tenducci marriage also was covered in a pop-history book a couple of years ago, if you're interested it's a nice read, I'd recommend it.