The project isn't the issue. 8.97 clearly doesn't like something with this somewhat newer hardware or Win 10 1909 as I can install 8.97 on my old Win 7 laptop (running DirectX 11) and don't have much issue with the exact same file being read from the same SD card. 8.97 does still use more CPU than 2.41 did and seemed to take 2-3 times as long on that laptop (I judged this on the Resource Monitor graphs) using a fresh install of each.
The new laptop is running DirectX 12 (as confirmed by dxdiag, which claims there are no issues), and I have finally been able to update graphics drivers for both discrete Nvidia K1000M and integrated Intel HD Graphics 4000 adapters. It doesn't matter which adapter I use and it performs just as it did with the Lenovo drivers. Upon adding the file to the project, CPU spikes to 98-100% and remains there for over 5 minutes. At about 6 minutes it starts to slowly comes down and will finally go back to nothing at 8-11 minutes (this is just for Videopad with nothing else running, of course). It won't display any video but will play the audio.
After another half an hour or so: Well, just letting Videopad sit doing nothing may have solved whatever was causing the issue. After a lunch break I started trying other video formats (3gp, avi, flv and wmv) and they were working so I tried MP4 again and it worked. The file I had already added still wouldn't play but deleting it and re-adding did work. WTH?!?!? I'm going to reboot for like the 20th time today and hope it still works.
Edited to add: it does seem to be working now. I have no idea what the issue was. Shouldn't have been Windows AV or anything like that as there was no disk (or really CPU either once VP settled down to < 1 %) activity. Something happened in that 30 minutes though.