It seems fuel filters should be more than capable of running a couple hundred hours of fuel through them so I go more on gallons filtered than season. Plus those dirty filters seem uniform gray like they're doing the job they're designed for(sort of my tank inspection?).

If I started clogging filters rapidly, then I'd say it was time to pull a hundred plus nuts and bolts, and the massive tank tops. A vacuum gauge looks nice, but it's also another thing to break(or suspect it's working), more joints to leak, and more work I'd rather not do.