Personal preference I think and dependent on how they are used. Manufacture doesn't recommend it for the drainage reasons and for reasons of the 'just in case the main stabilizer jack fail' it will cause excessive stress on the slide frame and mechanism. A lot of dealerships will say don't a lot will say its ok.
For myself, I utilize them, but understand, I just snug them up just enough to hold them in place and provide stability when people are in the slide area and weight is significantly shifted into the slide. I have had times when one of the stabilizers under the slide fell over after we (myself, DW and kids) were all in the slide area and we got up and left. This tells me that while we did not feel the weight shift in the TT while we moved about inside, the movement of the TT did occur, and that the stabilizer did provide some additional support. I have never had a run off problem because I have never adjusted the stabilizers so far as to lift the slide.
As a matter of the question of the manufacturer recommendations of not utilizing them, or of not adding additional jacks to the RV. Most manufacturers of automobiles and RV's will also tell you not to change rims, etc., or make any other modifications beyond what they do during assembly.
2015 White Hawk 25BHS Glacier Package
2004 Dodge Ram 2500, 5.7 Hemi, 5Spd Manual
2008 Arctic Cat M1000 SnoPro
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