From what i know UK can reach rep cap with 2 supervetted EBVE sailors.

If it's true than you can reach rep cap by superveting your reps.
Not really sure how many vets you need tho.

3 can as well as 2.

I am using using 2 repair and use 2 less supports than the suggested, and have a shitload of good repair rate.
If you don't want to scratch much your head.

Go
3 repairs + 7 engineers.
2 repairs+ 8 engineers.

The only crew that should be Ellite is Repair. Even roll engineers will be better than Ellite Engineers at high lvl.
If you're new and don't want to be perfectionist.
10/10/11 (rep/res/engie) are perfectly acceptable, solid crew, and is damn good. They are very very reasy to roll.

Do me a favour, just don't ever class and use restore man on your BB.

ok so having only 3 elite engys with 110-120 will still hit the cap right?! yeah im aware about the restorers thing been reading alot in forums.., but thnx again for reminding me :D

3 ellite engies only? Nothing else?

Rep cap is 280dps/sec right? Last i calculate my 3x lvl 118 +11 109 and 119 vets reps only do ~190 :(

If your engineers fail, don't expect to repair cap.
A huge ammount of repairs comes alone from engineers, it is why, if you want to make a good UK crew.
Better take the time to roll, else it blows.

Good 3 ellite repairs is a nice start.
Are you also getting 10/10/12
or 10/12
11/11 engies?

5x engy i think they are 10rep/11eng BVE all 109 vets and the reps BVE, 2 are 116 and 3 are 118.