I only know that it's related to the OP_RETURN value. Core v30 aims to increase the max data size while Knots is keeping it low to avoid malicious content being hosted by nodes. I could be very wrong, but that's how I've interpreted it
(Please correct me if I'm incorrect/inaccurate)
Correct! There are a few other useful things in Knots, but that's the main one, right now. It's a 100% compatible drop-in replacement that "just works". You dont have to redownload anything. It's a great choice if you think bitcoin is money.
Regardless of one's position on mempool policy, Knots is a virtue signal at best and a security hole at worst
It's developed by what's essentially a single developer without robust QA or review and with difficult to verify merges from core