It's just a design play. Electronic opisometers already exist: https://www.amazon.com/Calculated-Industries-6025-Digital-Measure/dp/B002O16VKQ/
...better grip, better reach, and smaller wheel too- so it's gonna be more acurate than a silver-dollar-sized wheel you need to hold awkwardly.
I actually use a digital device similar to this almost every day for measuring blueprints. Scale Master (Amazon)
It has a bunch of built-in scales to use, plus options for custom ones. I would imagine it would work well on a regular map besides blueprints.
Until you find your magic software, you might consider spending $50 on this:
https://www.amazon.com/Calculated-Industries-6025-Digital-Measure/dp/B002O16VKQ?th=1
I looked for software just briefly when I was doing my in-floor heating plan. Ended up counting graph paper lines, which was good enough for the one-time calculation. I'm sure it's out there, based on what I see on county auditor property websites around here. Whether you can stop short of full CAD to get it done I'm not sure.
Before COVID, I was doing this and loved it. I bought a handful of measuring pens and let the players do their own measuring. Measuring pens are great because you can go around corners and curves. There are cheaper versions of the Scale Master Pro, but I like this one that lets you change the scale on the fly.
I also have one...every time a similar “new measuring device” shows up on reddit I’m over here with my 30+ year old one like ??? They even already make digital ones with hundreds of reviews on amazon...
Calculated Industries 6025 Scale Master Pro Digital Plan Measure https://www.amazon.com/dp/B002O16VKQ/ref=cm_sw_r_cp_api_i_7FeBCbPPVYTT3
For building plan estimations I've used one of these in the past. I assume this is what OP is referring to: https://smile.amazon.com/dp/B002O16VKQ/