Dam said:

Agreed. Even without the use of custom components, towns remain fairly active. Only the Next Act Begins cards become almost completely irrelevant and laughable. Just because you don't see Innsmouth or Dunwich swarm as often doesn't mean they won't occasionally as an upleasantly pleasant surprise :')

We play with max 2 expansions, usually 1 small card-only + 1 big board expansion. This way we feel there's no problems with dilution and the expansions stay much "fresher" over time. Sometimes we use only 1 expansion if we want to emphasis a particular theme (yet we always use the Permanent Exhibition / Performance variants of CotDP and KiY), and we've thought about adding a third expansion sometime, but we're perfectly happy with just 2.

-Villain

I was using one big box and two small box expansions in my solo games, but I've been concerned enough about dilution to drop down to just one small box. I usually choose them randomly and just leave all the cards together, and then check for the expansion symbols before I resolve the card. I use all the investigator cards and monsters all the time, though.