would i be able to have non-oem boost gauges installed by someone other than a subaru dealer?

is there any part of the warranty they would void? thanks.

It should not affect your warranty if it is installed correctly.

If it is not installed correctly, Subaru might balk at electrical or electronics problems. It should not affect mechanical components at all.

Actually if it were installed incorrectly and leaked air into the intake manifold, it could result in a lean burn situation that in theory could cause mechanical problems. But you'd know as it would make it idle very rough, if at all...