Mine is set up with a 45 degree elbow or two between the toilet and the tank. Dumb design if you ask me.... But generally my only issue with it is not knowing for sure how full the tank is....
We haven't had too much problem with plugging. I think it has happened a time or two when too much paper was used.
Yeah, perhaps try the two flush method &/or less paper. Also be sure to prime the bowl, maybe half full or so, with water before any solids go in