Ya I was curious to know if that made the females spawn sooner?
It'll help them recover sooner, which could reduce the time until they spawn again.
I'm also wondering if people get more viable fry if they wait?
What does "viable" mean in that context? Capable of working successfully; feasible?

There's some belief that fry imprint upon their mothers during that period and if you strip fry, they'll be less likely to hold as long term once they start having fry of their own, especially with tropheus, sandsifters, etc. IME it's more of a European frame of mind on the topic and over here we tend to strip fry without concern.
Stripping also induces the risk of physical damage IMO. If the mother closes down somehow on the fry as they are coming out, they can become damaged/kinked or die. If you strip too early and have to tumble the eggs, if tumbled too roughly they can become damaged/improperly formed.