I find it helpful to vet my BO when he's actually my original yellow AA gunner...just a
stupid mistake. If you manage to VE your gunners though, I find that going acc-acc-acc
doesn't hurt too much. I don't miss the reload. I can still oneshot lots of stuff :D.
Besides, I find that it helps you learn accuracy if you can't fire shots every second.
(exaggerating here)

If you are doing a second line, I would almost suggest not spending money on gunners.
Grind them up on another ship/line to about level 60+ before using them with new crew (if
your set on playing in blitz level to around 40). This saves you money on boosts, vets
and experts as by level 60 you should have enough natural growth of experts to roll for
reasonable vets.

I have done this with last 2 crews and while without boosts they do cap a bit later the
significant increase in levels has kept them high enough for good spread/rld as I reached
next ships. My next lines gunners are at level 82/83 right now, with near full experts
and about around 100 vets. I expect to cap before I hit BB1, with no money in the gunners.

Only sailors I really see worth boosting and mass vetting these days are Engies, Fighters
and reps.

all accuracy gunner dont help in the long run tough. you'll have to wait till near monty
to rld cap.

tbh if you should BVE something on your ship, its your gunner, then your engies, then the
reps.

After a certain true ability level tough, only level will improve your gun accuracy, as
that cap is level based (only a certain fixed ammount of true ability is considered upon
the revision of the spread depending on your level, and each new level increase that ammount)

Another way to promote spread health other than what eshkidd said is to have
aiming FCS and make sure that you have accuracy gunners.

Thanks, any piece of info would help.

Three things.

Level - takes time
Vets - takes money
Boost - Quick and Simple but takes money