I remember seeing a post about parameter types where the user had a string that was actually a number, but could not explicitly call out the parameter as an int and something for this was in the works.
I would also like to propose that a "description" field be available for each custom parameter/property that shows as a popup when hovering over it in the property editor, similar to the way it does for default props.
This would be super convenient to document the purpose of each of the parameters/custom props for later (when I inevitably come back in 8 months and have to remember how everything is put together).