No, if your primary source of income is working on engines with more then once cylinder, compression gauges and leak down testers become mandatory. Then like a dump shite you loan them out and end up buying another because that guy didn't bring it back. Also nearly every engine has a water limit spec for compression psi. I'll give you a hint, it's not how fast it falls when you hang it by the starter.LOL. The one we got from Stihl doesn't read anything, as in zero. Bad valve I'm sure.
Anyway, If you need a gauge you need to work on more saws.