Thanks on the level update.

As for "..waste of time."  I think all of NF is a waste of time, but I do it for fun and the U-flak guns are a blast to use.  In fact, even though I have my SS5, I regularly take out my U-flak and rip apart squadrons of planes and absolutely love surfacing to finish off a burning Moltke...just for the sheer pleasure of doing it.

U-Flaks are sadistically fun.  So what if my gunners sit in HQ? They have plenty of company with my other unused sailors at any given moment.

its so popular that even this totally new guy has a question:  With the SS4, what's the pro/con of using say 2 repair or 1 repair and one support that you haven't classed as either Rep or Eng yet but has good ENG and REP skills in the gun slots?

Rep amd Eng should totally be on the support slot,i find km ss4(if thats the one you are talking about) have 2 aa gun slots,which is not of much use,to many ss players,they would use it as extra support slots since aa gunners on ss is not that much of a use.
Never place support sailors on torp slots in ss,restorer are a waste on ss, since ss isnt that durable.plus having more than one REST wont stack the ability while REP and ENG does.

HAVING A planesman and  sonarman is a must on ss!do not have more than one of each of these since their skills dont stack.

         ppl would have a combination of rep and eng to create a balance.while many would have more rep than eng for faster repair rate and less overheat speed rate

   while some have more eng than rep for faster speed,faster overheat speed rate and less repair rate.

    while some only fill in all the slots for rep and no eng at all or eng and no rep at all(this type of setup is other ppls' way of gameplay,but not recommended since both are equally important since ss can take higher damage from weaker shells than ordinary ships and are slow at speed)

  ss are even slower when underwater and will not catch up to most ships since ships are always moving at high speeds so engineers are strongly needed just like repairers

  sailors that arent classed to rep or eng do not have the ability eng or rep can do.Rep and Eng are way better than the unclassed,so classed the sailor into a eng or rep as soon as possible when they reach the lv required to be classed.

btw to answer that question,if the sailor rep skill is higher than the eng skill,class it to rep,if not class it to eng, if they are equal,then its up to you. Using the gun slots on ss as extra slots for more support sailors(not other ship types,only ss!NOT on the torp slots on the ss either!)  rather then putting aa gunners on is recommended

Sorry, but I have a couple of corrections:

Repairers perform equally well on any slot, they don't need to be on a supports slot (but you are right that engineers do need to be on a support slot).

Restorers do stack - in fact all sailors contribute to SD, whether they are restorers or not.