As much as I kept using firefox while it progressively got more unusable, I just straight abandoned it after 91, at some point time spent fighting configuring my browser to be usable is better spend choosing from alternatives.
Well, from what I've read all alphanumeric can be typed just fine, they go as is to terminal, problem is with special keys that some of them emit escape sequences that confuse shell or combinations of those.
But not to trust what I just read I've installed kitty and tested it and you can type in the "reset" just fine.
I hit a bit of a problem with "Entering" it, as apparently if you have numlock enabled (which I do on login) pressing "Enter" sends escape code: "^[[13;129u", but if you disable numlock it is typed in as per documentation: "0x0d - for the Enter key", which in any ascii table is Carriage Return.
And yes, issuing reset restored normal terminal operation.
The thing I would like to see is this making it into terminfo entries, meaning that it is possible to detect that terminal supports this behaviour, otherwise while great it is terminal emulator specific.
I guess same thing that happens to any application that sets weird modes. You should use 'reset' command which just emits escape code to reset terminal and terminal emulator hopefully sets everything back correctly.
You might want to take a look at https://github.com/trunkmaster/nextspace where someone tries to recreate the NeXT experience on top of noth GNUStep & Window Maker, both modified to provide coherent experience.
I think tcc is now community maintained, see "Savannah project page and git repository", and you can get there link to project git, which was last updated just few days ago. (http://repo.or.cz/w/tinycc.git) so seems to be active.
Current default is 100.
You can also use maxwin command (for example 'maxwin 200', up to 2048) in your screenrc file to define other value, no need to recompile.
However do note that you can't change it in already started screen.