I ran into a similar problem but my problem is not (yet) with the number of rows but with formulas. After creating a good number of formulas using all sort of capabilities in Coda, I started testing and a button that triggers another 15 buttons might take up to 10 min. to delete and then add 15 rows. I am quite afraid that all the time invested in developing the file would be wasted if it performs like this.
After a couple of hours of testing I realised that the things that slow things down the most are:
- Conditional formatting
- Formulas that include data from more than 1 table
- Cells that have an error (even when empty cell is an error)
In that order.
Removing the first 3 considerably changes the behaviour but then again makes the tables not very functional.
I don’t think that the local machine has much to do with the computing.
I hope that there is a way to improve that other than removing functionality.