That's exactly what I did when I had performance problems. I also had some processing that happened whenever someone submitted a form. I found that I hit a perf

That's exactly what I did when I had performance problems. I also had some processing that happened whenever someone submitted a form. I found that I hit a performance limit when many people tried to submit the form in a short period of time. I eventually found that if I changed how the spreadsheet was structured, a lot of problems were drastically reduced. I forget the details, but I think I switched to having one sheet that just collects form submissions and does nothing else, then another sheet that uses Javascript to pull data off the first and do the computations. That way processing was moved offline from form submission. But the general point is, you can't just write a spreadsheet, collect thousands of form submissions, and have no issues. You can't just assume "Google scales everything". N people interacting with N (or 2N or 3N if you share with a few) spreadsheets is an embarrassingly parallel problem. N people interacting with 1 spreadsheet is not.