The constraints that tend to happen with the factory ECM are dictated by what the factory designed it to do in the first place.
Something like using an EGT sensor to perform another task such as say boost or torque limiting based on the temperature reading isn't in the ECM code, 'someone' has to write the new code that makes the ECM perform that function. But you have to remember nobody has the source code for these ECM's but Cummins, nobody has a 100% understanding of what everything is doing in the ECM so adding in functions like that is very difficult and sometimes simply not possible with the limited knowledge the aftermarket has.
It would be like hooking up a WBO2 to a LS1 PCM and hoping it is able to keep track of AFR's throughout the entire AFR range, it can't because the factory never gave it the smarts to be able to do that.
From an EFILive perspective it is always a balance between keeping majority of tuners happy and updated vs things that minimal users would ever use that require a lot of R&D. Admittedly the 1% that like to tinker outside of what EFILive offers have probably reduced the request we get to expand what we currently offer in the software.