EMCO fuel filters do have a problem with ethanol... the glue dissolves, I have read.
But a dirty fuel filter should not allow dirt to pass through, it should result is a blockage of fuel and poor engine performance.
So, I'd say that your dirty filter did result in bad idling but the dirt that got to the carb probably passed through the filter even when it was clean.
Just a total accumulation of very fine dirt or gasoline residues. It is best to buy gas from stations that sell a lot of gas and therefore have fresh gas.
And Cheapest gas may not be clean gas.
Shell gas seems to be the best for our bikes & scooters... even if their ecology issues are the pits.
scoot safely,