They mention base64 encoding messages to evade filters. There were actually other base{n} methods [1] created specifically for Twitter to be more space optimized though not as readily available to operating systems. I guess this is less useful if they are really expanding the text limit to 4k soon but figured I would add it in the event they add a parser for base64.

This assumes most people would be able to:

    npm install base2048

I think it might be interesting if Mastodon added a function to automatically detect and decode base2048 for browsers in javascript since JS is required to view a Mastodon site anyway. Bots would then have to adopt this logic, rendering most bots useless until they adapt and evolve. But I am not a developer and maybe this is just not possible.

[1] - https://github.com/qntm/base2048