Also, I was surprised to find out that the Shimano Deore RD-M5100 derailleur, while it does have a clutch, doesn’t have a cage lock.
Yep, the cage lock is a SRAM thing, Shimano never had them, but instead they got a clutch engage/disengage switch which is nice but doesn't really compare.
Also be careful with the cassette change, if you have 2 or 3 chainrings in the front (I'm assuming because of the small cassette originally), the chain may be too short on some gear combinations and you can cause some damage if shifting there :p
Even if you have only a single chainring front, you should probably install a longer chain though