Lowest GPU I've tested on was a GTX 1070 which is 10 years old by now.
99% usage shouldn't be a problem on its own but those temperatures are pretty high. I think adding a fps limit should help to address GPU usage in a future build.
Would you mind sharing the exact model of your GPU so I can look into other issues that might be problematic. Thanks already for bringing this to my attention. Already gave me some spots to focus on improving performance in it's current development stage.