you should check out "yawmm", it's open source by cwstjdenobs and various other devs (Leathl, waninkoko, etc.). In fact, mmm's wad manager copied a lot of yawmm's code (which is one of many reasons why mmm should be open source, but that's another issue all together). yawmm offers faster speeds with non-38 bases like 56, 57, etc. It also has brick protection in place to prevent ppl from installing a stubbed SM IOS or uninstalling the system menu or SM IOS, installing out of region SMs, installing a System Menu without already having the correct SM IOS installed, etc.
Anyways, if you're content to leave your wad manager as it currently is, so am I, but I just wanted to let you know that the source for mmm's wad manager was basically copied from yawmm, which is open source.