Whenever the hitch goes up or down, the movement of the trailer end behind the axles also goes in an opposite direction. Putting weight on the tail of the trailer removes weight from the tongue, that will cause instability and tracking problems. If you have LP tanks on the front tongue, it would be better to extend the width of the LP tank base and mount the generators on either side of the tanks. The trailer is stronger in that area and the generators will be subject to gentler motion between the hitch and the axle.
Bob & Donna
'98 Gulf Stream Sun Voyager DP being pushed by a '00 Beetle TDI