Hello my first post here,
in our company we have the also the problem with correct version in FPGA without rebuilding the whole projekt and spend a lot of time.
Looking around for a solution i found this post.
The scripts are very nice. But i think a more time saving method is using a rom in the SOPC System and just updating the hex or mif file. You can read out aut the Rom with a nios or a JTAG Interface.
After you verified your fit you just modify the hex / mif then use the Update memory init. File funktion in the Quartus processing menu. If you enabled Smart Compilation you just need to restart assembling.
Currently i'm working on an autmated way similar to your tcl example to update the information in the hex file.