One note at a glance. The x3 seems to have a pcb ‘cover’ over the board. PCB’s are expensive. All that is is a ramps (basically) with a fancy cover and onboard mega. You have already experienced multiple failures, and with this any failure is another 110+s&h.
Most of the guys who have been doing this longer than I seem to be fans of the rumba , same basic design. Onboard mega, one board, no fancy pcb cover (more money into the board instead of fancy covers?)
So that kit comes out to 212 with the options added in. and is BO for 1mo + .
My ramps kit, with t2.5pulley belt, wires, steppers, sd ramps, hot bed, basically everything but 3 switches, cost me 180 shipped.
With how you are going threw these , my suggestion is to continue on the path you are on. As you blow them up parts will stack up eventually leading to a spare set imho. Many , many people run ramps with absolutely no issue , and not to be mean , it is probably not the board , but what you are doing to them causing it. That said my guess is the x3 will die a horrible death and will be more expensive long term. Unless you vaporize traces , those can be repaired rather easily if you know what you are doing. If you were local Id do it for ya but shipping is out of hand. It is really to the point the thought has crossed my mind to ask what you are doing with the blown ones.
Just my two cents. But I would personally ask @ThantiK if he has seen that board and his thoughts on it vs a rumba. He is a living encyclopedia of all things 3dp imho and I trust his opinions. But my two cents is this is going to land up being a really really expensive way to go , assuming you still have some learning to do (releasing magic smoke) atleast keeping to ramps in a pinch you can mail me some broken ones and I can replace the parts you smoked.
Worth noting This is the first i have heard of the board, and I might actually know the mfg, I know someone located there working on one but dono if they are this far. Im not really saying its a bad board, i really dono.