I just fitted 2 of my blade fuse adaptors, first 2 positions 1-2 and 3-4. Very tight to p[ush in, so there is no issue with quality of contact IMHO, although I do agree that adding extra points of contact is not a good thing. On 3-4 i wanted to check if the now wired up and switched heated rear window worked - no - it only showed 150ma for the indicator bulb. more research required up the back. No sign of a relay involved on the diagrams, or in the wiring.
on fuse 1-2 all I saw was~260ma - domelight. It should be 10W, but its very dim, almost yellow, so 3W is about right. Damned if I can get the cover off it, as I have a couple of LED festoons which should be brighter. or is there a known problem with poor wiring up there?
Interior lights in the 928 are known for problems with leads shorting to the body...I was actually down at the local Porshe workshop once having a natter, leaning on the back of a customer's 928 when we heard a clunk, and when we turned and looked into the rear hatch there was a wisp of smoke and the festoon bulb fell out of the rear interior light.....