Among other problems, this fails to account for non-typing activities performed by the monkey, such as damaging the typewriter or attacking the researcher.

285 years increases to a few thousand if you alarmingly frequently have to clean the contents of a monkey’s colon out of a typewriter.

And at some point you’d want to further “refine” your selection process by “repairing” the typewriter to have fewer keys and/or causing the typewriter to jam after the required key press. Monkeys like to press the same key over and over again. Good luck getting them to stop once they’ve pressed a key once.

TL;DR monkeys are chaos, and this will not be easy.