>Is there a way to tell LR to show POI markers?
No, it will only show GPS markers for images or gpx tracklogs.
>If not, is there a way to ask Adobe to consider adding this ability? Since the tracklog is simply an xml file, it would be a simple thing to do.
Put your request on Photoshop Lightroom | Photoshop Family Customer Community
If your logger has a date/time display on it, take a pic of the display -- that will make it easy to adjust the pics to the correct time back in LR.
It doesn't. Good idea otherwise.
I did find a workaround of sorts. I compare the camera time to a website showing the correct time and see how much off it is. Then I change the capture time by that amount in LR for all the photos in the group. It doesn't show the POIs which would be helpful for this, and possibly other reasons, but it does get the time on track.