My concern with that set up is the carto getting hot and burning the orings at the top of the
tank. If that happens, the
tank will leak from the top.
Also, there is a correlation between how full the tank is and how well it wicks the filler in the carto. I have been advised to never fill a carto tank to the top, that it would slow the wicking process. It has to do with air pressure in the tank. Some air is needed in the tank to aid the wicking. Also, if the orings at the top of the tank burn, then the seal of the tank will leak and probably affect wicking as well.
Otherwise, if it is working fine...then go with it