Now that OS6350 and OS6450 are no longer available, we're starting to deploy OS6360 as our edge switches. The documentation for the latest firmware (end of 2022) still mentions standalone and virtual chassis modes, but if you follow the instructions to boot the switch into standalone mode it will still boot into VC mode. So I think standalone is gone for good. Seems like AOS is evolving towards a single mode and commands set along all ALE switch lineup and I think this is a good thing.