Could it be an idea to have two sets with attributes: One read-only with all decimals (3?), and one read-and-write with the limited number of decimals (2?)?
Off-topic:
Anyone that have an issue inside MSFS with COM1-increments? I use COM1 with carry over, and it is incrementing between 5 or 15kHz.... and also both increment and decrement increases the values!
(But this has nothing to do with FSUIPC, and I guess this is a MSFS-issue as I do the increments/decrements using joystick-mappings for this)
