Pigtailing Wall Switches, Ceiling Lights, etc.

I have a 1971 3-bedroom cape with the infamous AL wiring. I was in the process of replacing all the AL wiring throughout the entire house but decided not to (way to time consumming). Instead, I am now going to pigtail all house receptacles and use the expensive purple caps. Question is, should I followup using the same process for wall switches, ceiling light attachements, and circuit breakers as well? Not sure how far an electrician would go in correcting this issue short of replacing the AL wire with CU. Any comments would be appreciated.