Any difference between Amazon and AbemaTV version?

There is no difference. The show doesn't air uncensored or with any different cuts on any source, TV or streaming, unfortunately. The framerate and timing are identical, audio is lower bitrate, and video has a variable bitrate with a lower average. I'd recommend downloading the Amazon version presuming it's the original. This was only uploaded to provide a lower filesize version, as AMEBA shave off 25% of the size, but still use h254. The compression appears to be okay. I've not really analyzed their releases frame by frame to check the quality empirically. It would be nice to release a proper h255 HEVC or AV1 release but no one, [anon] or otherwise, seems to have the skillset to contribute right now. I've read over some HEVC documentation and advice from anime encoding blogs to give it a go if there's demand, but I don't feel my knowledge is up to the task of hitting that sweet spot of the highest possible compression before artifacts appear. I'd be fiddling with quantization and psycho-visual options until it looks okay rather than using logic.