What's the general theory that we're going with here?
Do an Amber IPA that peeps can dilute down to an APA/Amber if they want, or do an Amber Ale that peeps can boost up (with, say, dex or candy syrup) to be an Amber IPA if they want?
Just quickly throwing an example into the ol spreadsheet, if we do an Amber Ale at ~5.3% (OG=1.050, 30IBUs (35% from FWH, 65% from cube)), this can easily be boosted up to an Amber IPA with 0.5kg dex/syrup & ~double the hops in the cube.
Though i'd generally prefer to brew stronger then dilute down if desired, it seems better/easier to brew the 5%'er so we can get lots more cubes out of the batch (as per MOC's suggestion). It's a piece of cake to simply increase the cube hops & chuck in some dex to get the IPA if that's what's wanted by the individual.
FWIW, that recipe from Mardoo with 85/5/5/5 seemed fine.
I'd probably drop the caramunich 3 down to 2, or swap it for Med Crystal - i prefer to get that "mid level" caramel from med crystal rather than the deeper/darker caramel/toffee from dark crystal (but i don't have much experience with darker crystal, tbh).
Also, i'd be inclined to go a bit of choc malt to hit some more toasty elements, though it looks like the Supernova should do that (?). Finally, if we want a (very) malty Amber, i'd be tempted to go some Melanoiden malt (namely 5%). However, it's probably best to avoid going down that route, as the heavier maltiness will probably get in the way of the hops, for both the AAA & the Amber IPA.
Similarly, is it worth looking at 10-20% Munich (dark munich, ftw!!) to get a little mellow maltiness. Again, not sold on this option, but seems like an obvious option for an amber ale.
All just my opinion, and quite happy to go with it as it is and see what happens
. Just throwing some suggestions out there for the discussion.
EDIT:
@Nullnvoid, depends if you can be bothered trying to get a second runnings partigyle. If we go high, then get some second runnings, we're probably only getting another 5-10 cubes off it (likely 5). If we go lower for a straight Amber Ale, we may well end up with an extra 5 cubes anyway from having a more diluted wort to begin with.
In a sense, we're kinda restrained by the mash size. So either way, there's only so much we can extract. Do we look at 22x 6.5% beers plus 5-6x 4% beers, or 30x 5% beers? Seems easier to just do the 5%'er and make for an easier brew day.