NZ_BenThomas and MilitantPoet - I too am very disappointed, but also not at all surprised, to find that none of the SET stuff is anywhere to be found in the GUI, either in Server Manager where the LBFO is, or in Hyper-V Manager where you'd expect to find it in the Virtual Switch area, and even worse IMO if you already have a SET switch and view it in the Hyper-V GUI you end up with very misleading information and heaven help you if you make any changes to it there. Maybe you're actually blocked from doing that, I did not dare try and find out.
I have an LBFO on one of my Server 2022 because it is a dedicated management interface spread across two stacked switches, and my Hyper-V Virtual Switch isn't shared with host management. I would love to convert this LBFO to SET but that doesn't seem exactly possible, or maybe it is just so nuanced I can't figure out.