I have not used this but just a suggestion, have you tried to write to the memmap location of the transducers scaling? ie: if you inspect a device via PAC Manager and then select Point Config you should be able see the memmap address for the upper and lower scaled units. Check the image below:
this shows module 3 point 0 from a PAC-R2. you can see the memmap address to change the upper scaled units is 0xF0109014 and for the lower its 0xF0109018. You should be able to use WriteNumber to I/O Unit Memory Map to execute the new scaling.
ie: result = WriteNumToIoUnitMemMap(pac_r1, 0x0xF0109014 , myUpperScaledVar);
I hope this helps
FWIW i have used the WriteNumToIoUnitMemMap command to successfully change the IP address of the ENET interfaces on a PAC controller. Probably not recommended but lets say you have a system with an R controller that has static IP's. what if you 'sold' this system to someone who wanted to put on their internal network (or what if the client changes their network config)? A change, store and reboot can all be done from writing to mem map locations. I believe this command can be a very powerful tool if used correctly.