read aloud feature in xreader as in okular but with auto page scroll

[OnlineLearningTutorials]

I want to work on a pdf reader text to speech project. Okular have this feature but it not have auto page scrolling, and okular works well if one page speak at a time, if we give whole pdf to read it just hangs for some time. Adobe Acrobat have good text to speech but it works only for windows, mac and android. microsoft edge have read aloud feature but it only works on windows, and linux version of edge not have this feature.
So I want to discuss whether read aloud feature developing is good for xreader and what tts engine is best to use espeak, freetts, pico tts, piper or mycroft mimic3. I think it have two phases of development, one of the phase development for proper paragraph and sentence highlighting when tts engine read those line, and another phase is to properly translate the words and symbols of the pdf to correct readable text, like ten to the power two and not hundred and two.