142guy;
Replacement is a simple matter with immediate and noticeable improvement when there is nothing special going on optically or electrically ...like your Interior Courtesy Light.
...but when its not a simple matter, like for instance LEDs where the emitters are nowhere near where they are supposed to be (H3 example):
(Source:
https://www.sw-em.com/Headlight_Note...Considerations )
...or for instance the AMP Indicator (which needs to pass a certain magnitude of current), or Directional Indicator Pilot Light on the dashboard of an Amazon (where the Lamp is tied across R and L circuits). Here further modifications are required when changing to LEDs...and frankly I don't see the point...those bulbs are undervoltaged in service, so very rarely burn out...so where's the advantage?
You are familiar with this, I'm sure, but for anyone reading along, see:
https://www.sw-em.com/OR-ing%20Circu...onal_Indicator
Cheers