Fuel Pressure Gauge

I have a fuel pressure gauge for the fuel rail of my EFI setup. I would like to leave it plumbed in to the fuel rail permanently. My question, does anyone see a problem with the long term use of this gauge?

Use an isolator between the gauge and fuel rail. Fill it from the isolator to the gauge with glycol. In case of a leak, fuel won't spray everywhere,

Looks like the isolator will be hard to package. There is a schraeder valve at the end of the fuel rail, maybe I can put an extension on the gauge and screw it on when I need it.

OR, maybe it's OK to leave these plumbed in?

The isolators for EFI are very small, check with autometer. The huge red one is for up to 12 psi only.