It would have to be, all of them use a full power section with output transformer, then throw a dummy load on the output transfer and tap off of that. The SWR, H&K, and Warwick all use EL84 for the power stage, interesting that SWR is the only one doing push-pull, the other two are single-ended.
This is still on my list and I'm hoping to get to it soon. I'm assuming EL84 was selected because it's physically the smallest commonly used power tube and is relatively low wattage so you don't need a massive dummy load like you would for 6L6 or EL34, but frankly to get it into a pedal EL84 isn't a great choice because of size, power consumption, and heat. My plan for the initial prototype is to use a 12AU7 in self-split push-pull, which gives about 1W through a speaker. This would keep power requirements down and allow me to use a smaller power transformer and smaller dummy load, making it my best shot at getting it into a pedal-size enclosure.