the critical SE actions are to establish best glide
That's an old one but I wonder where it comes from.
Statistically, a suitable landing site is equally likely to be near or far away.
The nearby option - in fact one nearly below and slightly to the left - is easiest to inspect for suitability.
So, setting up a lowest sink speed, which is considerably slower than Vbg, is likely to be better because it gives you most time to think.
Think about what happens if above an overcast. Vbg makes no sense at all.
Unless you have a GPS and you can see some place you specifically want to glide to, in which case Vbg is the best choice until you are overhead the place, and then set the lowest sink speed.
But even Vbg varies according to wind. For best glide range, with headwind, you want to glide faster than Vbg. With tailwind you want to glide slower than Vbg.