At the moment I have 45,895 text expansions in Typinator and a few in Keyboard Maestro that use KM's computational capabilities.
I'd go crazy if I had to manage them all in Keyboard Maestro, and here's my case for why Typinator is a very good synergistic tool to use with Keyboard Maestro:
Typinator 7 Update - #6 by ccstone
Since my memory is not what it once was, and the number of expansions is ever growing... I make extensive use of Typinator's Quick Search function along with the ability to have specialized categories of expansions that only show up in Quick Search when a specific prefix is entered.
I've used this critter for somewhere around 12 years now and am quite happy with it.