To be clear, I think you have a completely workable/viable solution for the application at hand.
I am suggesting an alternative in the spirit of a forum discussion. So if you search eBay for "detent potentiometer" you get a few hundred listings. If you search for "rotary encoder" you get thousands of listings. In either case there is software involved to convert an analog voltage to a discrete value - in your example it's a selector for 1 of 10 and the intermediate, non-detent, positions are irrelevant. But that's just your application and clearly if this was used in some kind of analog circuit such as for audio volume control you might need the continuous resistance adjustment between detents.
But let's say this was a mfg production (as opposed to low-volume hobby) application. For the scenario where you have 1 pin left on your microcontroller...and it happens to have analog (A/D converter) capability...an argument can be made that the design engineer might choose a rotary encoder with 3 resistors. That is, the software is frequently sampling the analog value anyway. It's now just a matter of the algorithm that converts a sequence of analog values into a discrete value.
Perhaps there's a few more lines of software to be written with the rotary encoder + 3-resistor method. So above is a eBay listing where in conjunction with 1 cent resistors the hardware is less than 50 cents. The software is written once whilst the savings vs. a detent potentiometer is gained on each manufactured board or whatever is being produced.
I completely acknowledge the incremental (vs. absolute encoding) nature of the rotary encoder method. But if your next application needs, say, 20 detents, or 30 detents, or "N" detents then your inventory of 10-detent potentiometers remains on the shelf. OTOH, you could use the same rotary encoder hardware and change 1 line of code which defines the number of positions.
Again, this is for discussion purposes only!
