Wow, @lewtun! thank you so much for all the amazing pointers you’ve given me, it clears out many of my confusions regarding how do I go about tackling this large sequence size issue. It’s very helpful. 
btw, I totally agree with the last point of yours, personally, I also don’t feel Natural Language is a good signal in capturing such a phenomenon, I’m actually trying to implement a paper where they’ve used such data for this classification, they’ve used CNN as feature extractor, so I’m trying to do it with transformer-based models.