We had a thread earlier this year where all the background, facts and speculation on the Sam Smith's music ban was covered in great detail so it would be worth having a look at it if you missed it. It's quite entertaining in its own right.
I think it extremely unlikely that Humphrey will relax the ban for the festival. He is hardly a thrid party in this. He owns the brewery, he owns the pub, he decides company policy. If anything,the landlord is the third party!
What is interesting is that his pub managers are resigning in droves because they are fed up with his draconian management style which leaves them no discretion in trying to make money.
Not drinking in the Plough WILL affect the landlord and landlady because they are less likely to meet their sales targets and therefore have less chance of receiving a bonus.
Unfortunately the only way to show our disapproval is to vote with our feet. Which is what is happening at many Sam Smith's pubs.