I tried an encoder similar to the one provided with the kit. Mine has detents, but it did not work well. Went back to the original no-detents encoder. Mounted a separate pushbutton on the front panel. The encoder often slipped when I used its internal switch.
The supplied encoder has a 6-mm shaft. So a knob for 1/4-inch shafts makes the knob motion eccentric. To overcome this, I took a large 1/4-in-shaft knob and filled the back, including the shaft well, with MinWax epoxy wood filler. (Oil the set screw so it the epoxy won't stick to it or infiltrate the threads.) After the epoxy cured and sat for a couple of hours I machined off the excess epoxy in a mini lathe and drilled a new shaft well with a letter "B" drill. The set screw easily breaks through the thin epoxy in the shaft well. (See attached photo.)
Jon Titus, KZ1G
Herriman, UT USA