Well, I just remember what it was like trying to get decals from the US - a nightmare, pretty much - the prices when I looked into it were such that you could only get one sheet per order or be slapped with import VAT and fees which added a tenner onto the cost of the sheet - so if I was able to see exactly where the nacelle flashes and the saucer rings were going, it would be a lot easier to paint in. The names and NCC numbers, I can make my own decals for, but I'd like to be able to paint as much as possible onto the miniature.
It's OK for the guys in the US - they've been able to order from ADB and from the US decal makers without limits - but it's a pain having to import into the UK all the time for the smaller bits you need for some projects. I had the same thing with Battletech - all the custom decal makers were based stateside, so importing became an issue...
I would ask that *any* engraved detail be as fine and shallow as you can get it while actually still seeing it though... not gouged out too deeply...