I know exactly your situation. I too, wanted a cover for the two burner stove top in my XT-276 and was unable to find anything.
I resolved the problem by making my own. I used a piece of plywood large enough to cover the range, rounded the corners, made feet from a piece of 3/4" dowel - cut into four 1" pieces. I screwed/glued the 1" long pieces of dowel on each corner, added a rubber cushion make for a chair bottom and then Cherry wood stained the whole thing. It looks good, matches the cabinets, clears the stove top/knobs and stays in place when traveling.
That Sir, was my solution.
2012 Fun Finder XT 276 Toy Hauler & Harley Davidson Ultra Classic with Condor wheel chock
2014 Dodge Ram 2500 AT 4X4 Crew Cab 6.4 L Hemi, 373 gears, tow package, Rambox option, Revolver X2 tonneau cover, Equal-I-zer anti-sway hitch.