Already dealing with the kernel 6.6.x difference to deal with the annoying 'waitforX' timeouts, this is moreso with piCore64 though with the v8 kernels, but the reported issue is strictly with Xorg on VC4 boards, namely PI0-3, not using the v8 kernels. The problem remains with piCore15 no matter how long one waits for the driver initialization to complete. Dropping down to piCore14 'xorg-server.tcz' on piCore15 remedies to problem for now, until the actual variance is found. Just loading TC to any base piCore15 image easily generates the issue on PI0-3s, due to their VC4 graphics, not for PI4-5 since they are VC6-7, and using the simple framebuffer 'fbdev' as reported in Xorg.log.