UPDATE: YES! That 1728 is really doing its work this time around. Pitched late last night and left the fermentor outside. About 14°C ambient. Full frothy krausen this morning. Moved it to the basement, in case the weather perks up. Which it doesn't like have any intention of doing, by it should be so lucky.
I totally know that feeling when you "f" up the first go-round and immediately want to rebrew the recipe, just to say you got it right. In fact, it actually keeps me up at night. I usually get about 2 of those a year and don't typically make it back to rebrewing them until about 10-12 mos later. Shame.
Yeah. Plus: half of the Clan already thinks every dark-red beer tastes like an abbaye ale(*) even if it's nothing to do with that, so I want to be able to make'm notice the difference, even if I forcefeed it to them by means of a bagpipe bong.
*) actually, they use "trappist" as a reference, for some reason equalling that with Rochefort 12. I have so much work ahead of me...
As for the 530 batch, you should split it half. leave half as is, and add some D-180 syrup and cane sugar to make yourself a Belgian Dark Strong. Then you got 2 for one beers.
As it is, it's already closing in on 10% ABV. I think addind more sugar to that would certainly kill it. And syrup...I'm loathe to add any of that post-fermentation. But I hear you: the malt bill is good starting point for something Strong, Dark, and, for want of better word, Belgian.