If you can separate the power drive rail from everything else on 5V (the buck chip, USB chip, LDOs, and LED circuit) so they don't explode, maybe you can do it. With a higher input voltage you'll be reducing the overall duty cycle quite a bit which will make the input caps' job easier because the high-side current burst they have to buffer is shorter. Honestly, the weak link in the buck circuit with a 5V input is the USB jack, and after that it's the inductor. The USB jack is rated for 1.5A, probably because for USB applications the standard only defines current up to that point. If you trust it to 3A that's 15W right there. At 0.85V the theoretical max current is a little over 17A. How about that, the inductor is rated for 17A RMS. So if you can jimmy the input to be comfortable with more than 3A still at 5V, the next thing to replace is the inductor. A lot of old gear, from S1 to RBox, have 0.47uH inductors on them probably good for over 30A. Now you're cooking with gas. The FETs are actually rated for close to 100A if you can keep them cool, and at the gate voltages that driver gives them they should have an Rdson between 2 and 3 milliohm - on par with the internal drivers in everyone's favorite TPS53355 (which has a 2mOhm low side and 5mOhm high side switch). A lot of 30A 53355 VRMs have three 100uF ceramic output caps; so does the Compac, but it also adds a 470uF tantalum-poly cap with 30mOhm ESR for extra buffering.
If you do separate the 5V chip supply from the main power (which techically could be done by drilling out a single via) you can circumvent the Compac's real high-load Achilles heel, which is its lack of ripple isolation at the buck driver. I have a 2.2uF cap at the buck chip to help decouple, but that's not so useful when you're looking at 15-20A current kicks on the input during a high-side switching. If that kick drops the input voltage below about 4V the buck resets, which means you don't get stable power on the output and the RMS voltage is lower than your setpoint says it should be. Isolating the chip supply's 5V line from the power swiching supply with something between 2.2 and 4.7 ohms resistance will cut down a lot of the brief input voltage tanks and keep your core voltage stable, which will allow you to push the chip even further. It's humorous to say, but with a very few changes, that little stick miner could push enough power through your ASIC to catch it on fire even with that giant-ass heatsink and still on 5V.
Im'a look to see what I can jimmy up from my dead NRBs I'm sure they are running with them TPS53355, nothing beats hashing out the magical blue smoke
just for lolz, reading your writeup on cube OC'ing on your website (all about the TPS53355 and feeding the BE100s with more power), relevant information is still relevant!