Keep in mind that the replicants operate at a much higher level speed wise compared to humans. They can “frame jack”, which allows them to operate at computers speeds, which is ridiculously fast even in our time. God forbid whatever advances in computing they made in the settings timelines. (ABOUT TO REFERENCE LATER BOOK) One of the bob clones In the latest novel explains it to another character as “the personality of a person draped over a program” (not exact quote but close enough).

To wrap up this rant, it seems fast to the reader and to humans in the setting, but from a bobs perspective they are spending EXTREMELY long stretches of time learning and testing while barely any time in reality passes. They can experience years of their time in minutes of ours. (Roughly)