If I’m not mistaken, the TF ex flow numbers for that head are achieved using a 1-7/8” flow tube.
So, with your 1-5/8” headers...... you won’t have ex flow quite as good.
You are correct, the TF spec use a 1 7/8" flow tube. On a similar note, when I asked Mike for a recommendation using TF heads and TTI 1 5/8" to 1 3/4" step headers, he came up with a single pattern as well. Another person using Mike's program, also, not surprisingly, came up with a single pattern, just using different lobes. So I am going to guess that there is something in his program that dictates single pattern. My application is different, but share the 110 separation and pattern as the OP's recommendation.