Might was to view this video just for the heck of it:
Or just look up "The Fit RV". Kind of gives you an idea of how stuff works, or doesn't work.
I've always installed jets (tornado, no fuss flush etc.) in our tanks if they didn't come with them. On some, I installed 3 in different locations and ran my own new tubing. Never had a failure or issues with a tank. Most tanks or easily accesible to install a jet. Some of the ones I've done required using a 90 deg attachment on the drill to make the hole.