I am aware that there is a 1 to 1 rule for a Fronius AC couple, I understand that you shouldn't put a larger Fronius than Victron, but can I put a smaller Fronius than the Victron. I have a 15KVA Victron system and I would like to add a 5KVA Fronius as the AC Couple connected to the AC1 output. Would this be a problem as you don't get a 15KVA single phase Fronius and the roof space I have for the panels for the Fronius is not large, it can take 12~18 535watt panels