Every year around this time, this topic comes up. I believe what we are experience is the summer blend of the fuel.
What I have done is readjusted my floats to 24mm x 5.5 mm and so far that cleared up my problem. I dont want to speak too soon but hopefully this does it. I am finding that I may need to change the e-tube for compensation.
I use to run my floats slightly higher than recommended because of the canted intake but I dont think it make that much of a difference.
I too have used higher octane or fuels without methanol but it is difficult to find.
You may want to check you float levels and see if this helps.
If it does continue, my next solution is like what one member said sea foam.
I use an electric pump and sometimes forget to turn the pump off before shutdown. I will not start the car just to run the bowls dry. It actually holds alot of fuel
Please those trying different methods post your results. I am curious to see the out come.
I am runn the spaces too.