Had the R5 for a couple days and also got the RF24-70mm 2.8L IS lens. Biking up at my local trails, snapped this hand held at .3sec f13 iso100. Never thought dreamy waterfalls would be possible without a tripod. 100% crop below.
Whats your slowest shutter speed hand held that stayed sharp?
This is Copper Falls in Wisconsin handheld 1/4 sec, F20 using the EOS RP (no IBIS) and RF 24-240mm IS at 24mm. I did not need it for this shot but this combination gives a high % of acceptably sharp pictures at 1/2 sec and some acceptably sharp at 1 sec exposure hand held.