I don't know how many ways to say it, or how many times it needs to be said, but here goes:
NEVER, EVER change the ink limits on an existing media configuration (aka RIP-based profile). The moment you do so, you completely invaludate the configuration, and there is no way to get it back, short of reinstalling it from scratch.
This is true for all RIPs, all printers, all resolutions, all inksets, et al. Don't do it. The media configuration is built upon the ink restrictions, and changing them changes everything that takes place from that point forward in the profiling process. I am assuming that the reason that you are looking to change the ink limits is due to some dissatisfaction with the performance of the existing profile. In that case, the proper solution(s) would be:
a) Obtain the tools and training to build them yourselves - (this is the best answer).
b) Try another configuration/ profile.
c) Live with it.
Bob