I'm only going by what it says on the Gov uk website. It could change of course and they could certainly backtrack.
''The grant will be 80% of your average trading profit, divided by 12 which will give a monthly amount. We will pay this or up to a maximum of £2,500 a month, whichever is lower.''
If my average annual trading profit over the last three years is £37,500 per annum x 80% is £30,000 , divided by 12 which will give a monthly amount of £2500. They will pay this.