I have the Tel Tru oil thermometers, which are plug and play in replacement of the dipstick.
They do the same job, though perhaps just a bit slower than a coolant temp gauge. Lot easier to install. Like 2 minutes top.
220* and under and you're good.
They sell them in 2" and 1 3/4" gauge faces. The 2" with the Kuryakyn trans covers may just rub a bit on the cover, the smaller one won't.
Looking down when riding, the skinny sweep hand and small numbers can be a bit hard to see, so I cut sliver of black electrical tape and laid it over the 220* temp on the gauge face. As long as the sweep is below the tape sliver, I know I'm good. I have never had either bike exceed 220*, though it's got to that high sitting in traffic (at which point I shut down until I can move).
The Tel Tru dip has an oil level line, but I only check oil level with the OE dipsticks (kept in my tool box). Neither of my Interstates has ever lost or burned any oil, at all.
They snug up with a wrench, so they can't be stolen with fingers only. They must not be tightened or untightened with the gauge face, or you will change the thermometer. If that happens, they can be readjusted in boiling water (212* at sea level).
https://www.teltru.com/section/95/honda-motorcycles