Sir Buckmarble! (Bow... Bow... Kneel...) Mavrom has been my favorite for some time and it's always the primary rom on my D3. When using the OC feature though in 4.5, I too experienced random reboots, or reboots at nasty times when a phone call started to come in. But I've fixed that, at least for me - I don't know if others looked at this or if a possible resolution has been posted here yet, but here goes...
Looking at the .d scripts, I see that you've included the GPU OC too? I learned something about my own D3 device while working with my own rom build (newbie yet) with overclocking that helped me out with MavROM 4.5.
I can OC this device stable to 1.2 (and probably can push 1.3) - as long as I don't OC the GPU also. Once I start OC'ing the GPU at the same time, I start encountering those random reboots or shutdowns - as well as some heat. I can OC the GPU fine if I trade off to a lower CPU OC. I've edited the .d script to comment out the GPU OC in MavROM, leaving the 1.2 CPU OC and I run a lot more stable now without reboots or odd slowdowns (and cooler even). The CPU OC definately gives me greater performance, the GPU - doesn't actually do much for me (but that's me).
In your next toolbox version, can you add a couple scripts for the OC options with / or without / GPU OC?