Well the X3 bios only works on the X3, and I wouldn't be surprised if their next X2 bios only runs on Xecuter chips (for whatever reason). I'd applaud that and think it's a savvy business decision. Then we could see how useful certain free and legal OS's are...
Now... would EvoX tie their bios to only launching EvoX? I doubt that'll ever happen; they have no reason to do so; you could probably circumvent it by naming your dash of choice to evoxdash or just launch into your dash after evox boots with minimal inconvenience. Plus, EvoX isn't being enhanced anymore, so what would the point be? As a corollary, they should tie their bios to *their* chip, and let all all of the other chips go without a working 1.6 bios. I think it would help the sales of their chip, having the only non-xecuter 1.6 bios solution, but I doubt it'd happen.
I don't want to characterize the issues between Xecuter and Xodus as bad blood, because that might imply that Xecuter gives a flying fig what Xodus and their userbase think of Xecuter and their products, but I do think after all that has been said and done if Xecuter found an easy way to make their bioses non-functional on the Xenium, et. al. without hurting performance on their Xecuter 2.6s, they'd be inclined to do so.