I do think it would be more normal to have a filter before the injectors, with a separate regulator, but this setup is not altogether uncommon on cheaper cars and bikes.
Emil at Custom Morgan is doing this and getting more even firing as indicated by reading the plugs and a more smooth idle.
My plugs read one side more rich than the other side, I get a lot of pop and crackle backing off the throttle and I have no leaks in the intake system. It boils down to uneven fuel distribution.
