There are going to be opposing views on the dangers of high VTF. Some would say it's better for the stylus to remain firmly seated in the groove, even at a bit too high a VTF, versus being too light and risking mis-tracking, or even bouncing around in/out of the groove.
If I found out I'd been running a cartridge at 2.9g for (say) a week by accident, I'd correct it but wouldn't sweat the "what ifs" about whether damage may have occurred. Quite frankly I'm surprised an Ortofon 2M could hit 2.9g without bottoming out, since they're already low riders by nature and have fairly compliant suspensions.
FWIW Ortofon's high-end MC's are spec'd to track as high as 2.5g or 2.6g, and I think some SPUs may be even beyond that.