Sometimes the TCDS or AFM specify a certain make or model of compass so be sure to check that. In some cases those specs have been altered by a subsequent TN from the manufacturer giving guidance to the installation of additional equipment to allow for the possibility that the originally specified equipment may no longer be available (Schleicher for one has done this). God knows why but the manual for my ASW-15 says that if the compass cannot be corrected to within acceptable limits when installed in the panel, it can be installed on the cockpit sidewall. In Canada, flight rules require a magnetic compass even if the TCDS and manual AND airworthiness requirements for pure glider don't. The regulatory requirement is the only reason I have one in my ship and it would be the same even if GPS had never been invented. Where I fly the compass is useless.

I'm sure the F35 has a magnetic compass. Odds are it costs $250,000, was designed to do triple duty as magnetic direction indicator, disco ball and contractor cash flow enhancer and averages twelve hours maintenance for every hour in the air.