Thanks again for setting me on the right track again, this is really appreciated. In my case I only included 2 potmeters on the console: one for rapid traverse override and one for feedrate override. I copied this from a DMU 50 console which we have at work...
Using HALshow and setting halui.rapid-override.direct-value to True (1) and then setting halui.rapid-override.counts to a manual value (I discovered that a value of 10 corresponds to 100%) works well together with QTDragon_HD. With that I mean that it will probably provide me with the functionality I need. I already wrote some HAL lines using the lincurve component to ensure that the output of the potmeters correspond to the tickmarks (it is not a linear scale...). By setting up the right net statements I should be able to connect these and have QTDragon follow this setting on the display. Same for halui.feed-override.direct-value and ..counts.
@cmorley: Luckily I didn't include a jog override pot on my console, as I now understand from you that this would not work in a similar manner. I did already buy a pendant (XHC with cable type) and maybe I will run into issues once I try to get that connected. For now I first want to get the spindle and servo's running

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Thank you all for helping me further.