I guess the solution to power disconnects and overloaded power outlets, is the locking IEC ends, or the locking Neutrik PowerCon ends. And carefully check each plate amp's max power draw and do not not plug in devices with total current draw greater than the capacity of the given AC breaker.
As you have to check when using ANY
electric draw. But, that doesn't take into account the "bursts" of power (crest factor) that is prevalent to audio amplifiers. For my rig, it was all Neutrik Speakon cables, so there was never a disconnect. But, in your scenario, 4 speakers would require 2
plate amps, but only a single rack mounted amp. And, if/when an amp channel smokes, most rack mounted amps can safely run at 2 Ohms to finish a show. No prosumer plate amp, that I am aware of, can run super-low impedance loads like that, in case of an emergency.
Probably the best advantages of class D plate amps, besides less weight, fewer racks to deal with, less pack space, are:
1. Their power supplies can take anywhere from 90 V AC to 250 V AC input. World power supply, and don't care if the voltage is sagging low due to other devices drawing power ie lights.
2. The power cable feeding the plate amp can be thinner gauge wire than the audio power amp output cable it replaces. Because of the higher voltage. So cheaper easier to roll up cable.
3. Less power loss, and therefore less risk of heat melting the cable, for any given longer cable run length. Due to less amperage carried on the cable, due to higher voltage being carried, compared to audio power amp output cables.
amps are susceptible to power droop. And, almost all modern amps contain around-the-world usable power supplies
2. This still doesn't negate the fact that you have to run 2 lines to each one! Signal and power. Add up the extra weight of the 2 cables, and it could be a wash, but the advantage goes to speaker wire, for easy, single cord setup.
3. Again, they all suffer from power loss. Be it from the mains to the amp, or from the amp to the driver. But, again, you are running 2 separate wires all the way to the cabinet.
Conclusion: is there a place for amps built-in to the cabinets? Of course there is. If you want to put a plate amp(s) in your cabinets, chris_c_, you do so at your own peril. Bill's cabs were never designed for, and he has always been against, installing built-in amps. The guide lines are the designs must remain air-tight, you must not block and pathways, and you cannot change internal dimensions.