Triacs are not the most reliable either for the application... and when they fail, they do it with a loud noise and lots of smoke. Funny thing about that factory smoke... once it escapes, its a real bitch go get it back in.... one day they will invent a patch kit for that, same way they did for bicycle tires.
Until there is a better solution than relays and/or contactors, or whatever you want to call them today, that will work with high current, inductive loads, I will stick with what the equipment comes with.
BTW... with all these ideas your coming up with, how come your not working for the manufacturers R&D department trying to design a more efficient, bulletproof, less expensive, heat pump or condensing unit??? Your an EE right?? You can do anything cheaper than a pro can.....