Need for Atari ST keyboard replacement exist for long time - like 2 decades. Because keyboard is not something lasting long, can be damaged, etc. One of first was Eiffel . And as I see it is still most compatible. Especially V3: WEBpage (https://didierm.pagesperso-orange.fr/eiffel-e.htm)
It has even classic Atari 9 pin joystick ports. And not available now, as I see.
Why it is better than NetUsBee or new Imposter ?
Because it emulates very well IKBD chip and board of Atari ST (what is practically same on all it, up to TT, Falcon) . NetUsBee goes not on that serial connection (what leads to ACIA chip), but to cartridge port.
And that means that needs own driver, what hooks on TOS keyboard, mouse read code. And what with SW what does not use TOS functions, but own code for input read ? Answer is simple: will be not able to use them - will not respond on keyboard, mouse controls.
And what SW is such ? Some think that mostly demos are it. Actually, there is plenty of games which have own IKBD code - for keyboard, mouse, joystick(s) . Percentage is about 40-50% . And not only games.
Imposter: designer of it talks about not emulated 6301 (IKBD chip/microcontroller), and something incorrect about Eiffel, as I see . Well, he has chance to improve it. Although, there is no real help from AF users.