Spring loaded dials

Says here that Digitech Hardwire pedals came with a locking ring so you could lock the pot in position by twisting a collar. Made it a bit difficult when you wanted to change it, of course. 

I think the problem you have is, well, really, cosmetic. ;-)

https://www.ebay.co.uk/i/202784461871?chn=ps&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=202784461871&targetid=522579827663&device=c&mktype=pla&googleloc=1006904&poi=&campaignid=1782815712&mkgroupid=70885936682&rlsatarget=pla-522579827663&abcId=1139126&merchantid=115015995&gclid=EAIaIQobChMIqODyqKPz5AIVitDeCh0cPgmVEAQYAiABEgIGEvD_BwE

That's a difficult one. I've seen spring return potentiometers (release knob, it spring returns to the zero position) but I've not seen push in pots before. 

With potentiometers, if you do go off piste and don't use a standard 16mm, things get complicated very quickly. I use a lot of 9mm panel mount Alpha pots (as well as 16mm Alpha) and Bourns PTL illuminated slide pots and tall Song Huei panel mount trimmers. These are relatively common but still monstrously difficult to get.

A lot of synth DIYers get together and do group buys from sources in Taiwan (etc) as some components like this are rarely manufactured - or rather, manufactured to order, so there's a minimum buy of, say, 1000 or 10,000. Which is a bit inconvenient when prototyping a pedal. Ibanez will, of course, have the purchasing power to buy these in bulk, average pedal builders certainly don't. 

I was looking just now to see if there's any such creature as a "locking" potentiometer, but I've not come across anything, not something which would fit in a Hammond enclosure, anyway.