I didn't think it was relevant as this was one only particular gig.

Obviously many venues and rooms aren't suitable for standing and I wasn't suggesting that it should be either universal or obligatory practice.

Re wheel chair access, every effort must be made to ensure this is possible. Also for disabled people in general.

I'm not sure if the legislation applies to all entertainment venues or not? However, there are certainly some "folkie" places where access is difficult e.g. Edinburgh's Wee Folk Club and, over the years, many clubs have been held in cellars, lofts and "wee rooms" in general. This was part of the charm but, obviously, we need to be much more inclusive these days.