Probably stupidly, I am going to weigh into the debate on calculators, Excel spreadsheet, etc, and time for shot.
Last is easiest; there is always a timer for match play and I assume it will apply on 9/21. I don't really care whether it is 90 or 60 seconds. As someone who prefers 90 sec clock, it only ever comes into play if I screw up like hitting rough. From fairway or putting, it doesn't make a difference for the top players.
On calculators or spreadsheets, why not. They are only guidelines. Every hole is different ... add yards some, subtract on others. Effect is of wind left-right is different on different holes, even on same course. The estimates are still there.
Of the players in the final 4, the one I am most familiar with is fmagnets, who is a WGT friend. He estimates his left right break. He doesn't really worry if he is 3 or 12 feet from hole. He sinks his putts. Anyone who wants to be the best in this game (not me) has to learn that closest to hole isn't often best; leaving the straightest uphill putt is, which means figuring out where to leave the approach shot on 13 and 14 green speeds is critical.
But if someone wants a more "precise" calculation … fine with me inside 90 seconds. It still varies hole by hole, plus when WGT says 18-20 mph (probably often more like 17-21) hey they mean that. So the shots will vary anyway.
My understanding of WGT rules is that any programs that piggyback on game are illegal! External aids are OK if they do not interact with WGT. The latter is totally un-enforceable for all of us (live setting different); the former is and should be enforced stringently. We should make our own shots.
And, if that has not changed, who cares if it is a calculator or a spreadsheet.