Yes, separate power supplies would be better. In all design undertakings a significant piece of the art is cost-effectiveness. Bill and I discussed various solutions and agreed that a more robust supply with various isolation techniques increases the advantages to both channels more so than the isolation effects of two separate supplies per se. Of course, that's considering cost. Since the supply will be separate, two could be purchased and assigned to separate channels. One of these days you could report on the relative value of such a choice.
More generally, my goal is to find the next plateau on the value curve, optimized at higher level(s) of performance that stock Thiel. Those levels / plateaus will settle over time. I already know that Jim Williams' first level upgrade, coupled with simply moving the stock crossover from behind the woofer to the cabinet bottom - are transformative. That will not be a product. The first product will use the same Vifa woofer and its alignment, but a different (post 3.6) midrange and tweeter with better XO components.