On departures there are two potential bottlenecks. The first one is the airline checking that you have the proper documentation to be admitted in the country of your final destination and leaving France. I doubt that the paid service can help.
The second one is French border police, but formalities tend to be quite fast as they have few cases with reasons to stop you exiting France .

On arrival you might have checks for health status (possibly some rapid test at airport) and border police. The process takes longer.
I side with Goldorak that the odds of long lines are much worse for arrivals than departure.

But if you are willing to pay both ways, just do it.