Right you are, with the 4 petal block it points the intake straight up into the frame, with almost no clearance to even get the engine bolted back on, and nothing to add on to the intake to move the carb elsewhere.
If you want to do 4 petal on Tomos you need to make a custom intake. I have the Malossi 4 petal and 21mm PHBG now, I'm trying to find some raw materials to make the intake. There's not much clearance for one, the pipe would have to enter the baseplate at an angle and bend 60 degrees or so to put the carb alongside the frame (airfilter pointing backwards) so you could still pedal.