Supposedly this airplane does over 125MPH with a DLE55 and APC20x12 clocked with radar and GPS?
This is far more than I expect so I don't know how they were doing it. Maybe with an 18x16 prop. The fuse doesn't have a tunnel for a pipe, so that would be a lot of work.
The USRA unlimited racers run methanol in Walbro carbs without issue for quite some time (a whole season) before overhaul. This first is hand from people who are directly involved. These guys run highly modified engines and if they were running gasoline it wouldn't be pump gas so the cost of fuel would probably be even greater for gasoline than methanol. When they are spending 20kUSD per airplane and have more than one or two for a race, I doubt the cost of fuel or carb rebuild kits is a concern, just the cost of doing business.