The der's wrap capacity is about how much chain will get taken up, not whether the der guide pully will give cog clearance. The minimum chain length is about being able to not have the der ripped off the hanger when in the big/big ring/cog combo. So if you have a long enough chain and not a rear der that can completely wrap that chain, given the ring/cog numbers, then the chain will droop when in the small ring and "some" of the smaller cogs. The question then becomes will you ride in these ring/cog combos that have chain droop? (And I would NOT suggest asking the other side of the equation- will you use the large ring and larger cog combos if you should set the chain length to not be long enough).

So will you be able to limit your ring/cog combos while riding? Many can, a few don't seem to even pay attention to this shifting/effort relationship at all. Which are you? Andy (who has done this exact chain droop choice before with no issues)