Yes, the board will be quite comfy with a 5.8. You jut need to take slight care to not push the fins too much just then going into planing, but to let the board get up to speed a bit first. This is basic wave board technique, but since the quad setup give the impression of having lots of grip from the start, it is easy to be "tricked" into overloading them in the accelleration phase. If you get up to speed a bit "easy" on the fins they will then take huge amountf ov power and track upwind really well also with a 5.8.
In the other end of the spectrum I would say that the standard combo handles 4.2 sailing surprisingly well. The more critical the wave performance (big fast sideshore waves) the more you may want to consider a smaller set of front fins, like the 13cm. It is more matter of softening the reactions of the board up a bit than to tune it for smaller sails. Ie there are no tailwalking issues or anything like that. In any case you should try the original fins first and see what you think.