I think its something to clarified , the artist should be asked how they feel about the use of the space , the putting out chairs aspect i would not want to see it all the time , but on some nights its would be fine by me . My reservation about the chairs at night is that if people come to see the show then its going to be quite intrusive ,
but at the same time encouraging people to stay within the space via seats and stuff has its benefits too. At times i feel standing looking at art solely is probably not the best way to enjoy it , and that a seat , coffee and some chat whist in the company of art would be more beneficial in that its has relation to life , rather than a rarefied experience in isolation via the white space
but i can also see your point bill about a quite area , of which sometimes i would like myself when theres something on in the cafe , and it happens anyway, its a unique feature of the gallery space .
just some thoughts on the issue ,