What a cool experience! Thanks for sharing that, Chris! Personally, I like the way you describe your decision-making process and how you collaborated with your client.
As to F# maj., I wonder... About the tuning you developed based on the temperament you started with, here is a thought: "it is what it is." (In the remodeling/building trades, sometimes we say that--"it is what it is.") Meaning, you tuned it right, and the temperament showed itself. So, your thought, "maybe a milder temperament would work better," is a fair one. Also, sometimes, in the remodeling/building trades, we use the expression, "Puttin' lipstick on a pig."
(I'm not saying that that's what you were doing, just saying that it is a useful expression to keep in mind!
Did your client have Internet access? The accutuner manuals can be accessed online: here.
Headslap moment? LOL! I have them about five times a day--when I get home and the day is done...
With online access, you could get to rollingball, too!
Thank you so much for this post, Chris. It's a good one! You'll have another chance to work with this client, right? (That is the most important question!