I may have messed up here.....

Material does not change mechanical compression ratios. You can ignore the "subtract one compression point for aluminum". While there are some thermal differences with running aluminum the effect is less dramatic than that. For purposes of camshaft choice use the calculated static compression ratio. The TF240s have a 78cc chamber according to what I've read (full disclosure - I haven't held a set personally). The problem is the flat top pistons with only 6ccs of valve relief and using the KB calculator that yields a static ratio of 11.8:1. Too high IMO and not needed for your intended use. What you need is SRP p/n 345809. Those are a 24cc dish and would give you 10:1 with the same Felpro 1009 gasket.

Edit - you're building an RB based stroker. You will not be disappointed. This adjustment simply makes the end result easier to live with.