My opinion would be a hard NO in almost every case.

When you jump into another form of paid flying, you're outside of the ALPA/ASAP umbrella and your ticket is at risk. How lucrative can that side gig possibly be? Is it worth even a 0.01% chance of endangering a multi-multi million dollar career?

What someone else said about keeping ties if junior isn't a bad idea. But IMO I wouldn't try a side gig to do it.

As for money, will that job pay a lot more than a WS or GS over the same timeframe? Seems highly unlikely even from the money POV.