GameTranslate uses RapidOCR, which is essentially PaddleOCR in a different format. They use the same models (Paddle's models). However, there could be differences in their output due to conversion errors. My implementation of RapidOCR is likely not perfect, either.
Unfortunately, the Paddle models only work for CJK & English at the moment. There are some Paddle models for other languages out there in the wild, but some of them seem broken and I just haven't had time to test all of them. The English models do have issues with spacing sometimes too. I'm looking to update the English & Chinese model to the new ones they just released a week ago. Hopefully it will be done soon.
In regard to other OCR engines - Yes, this is likely to happen, although they may not be more powerful. I would likely add another one just to be able to support more languages as Tesseract is subpar when it comes to anything non-documented-like.