Can I make a suggestion?
If you are going to change the number of presets then I think the default should be 128 so that current users of presets (including myself) are not affected by any changes.
A new system could include an option in the plugin menu to “increase preset slots”. Then the user could enter any number (not just multiples of 128) which would be added to the current number of slots and this number remembered by cantabile for this instance of the plugin.
This should help to minimise the size of cantabile’s rack files compared to the option of just increasing the slots in multiples of 128.
This option could be selected at any time and not just when the plugin is first inserted.
I hope you don’t mind me adding to your workload.
Sorry I haven’t got to look at this yet (super busy wrestling with the new Bindings work I’m doing).
Also, on thinking about it more I’m wondering whether a better approach would be to just make the preset list completely dynamic - ie: add as many presets as you like. But, that’s a bigger job and I haven’t had a chance to work through the ramifications of such a change.
I’m planning to take a few days break from bindings to tackle this and some other outstanding issues, either later this week or early next week.