Maybe I’m going backwards but I like the small propane bottles as it allows me to move my grill anywhere I like with ease. If the wind picks up while cooking, just pick it up and move it around to the other side without having to drag the tank as well. The bottles also fit quite nicely in my propane compartment so storing them is easy. Works for me but I can understand your desire to tie into your existing system.
2008 2500hd Silverado Duramax
2011 Northern Lite 8.5 lite
2006 Wildcat 27bhwb fifth wheel
2009 Lance 830 (sold)