Individual PB's and Team PB's. Not all sports are individual efforts. Simple example normal bike and a tandem.
I can't think of many sports that might have this problem as most gain speed from individual effort.
In cycling it would be the difference between a normal bike and a tandem. Being able to have a PB section separated into the two different bikes would be good.
Speed Kayaking might as they have crew boats.
I am looking at this specifically from rowing.
With Rowing you can take part on the water in different sized boats.
So there are lots of combinations -
Single (1x) - 1 person (2 oars per rower)
Double (2x) - 2 persons (2 oars per rower)
Pair (2-) - 2 persons (1 oar per rower)
Quad (4x-) - 4 persons (2 oars per rower)
Coxless Four (4-) - 4 persons (1 oar per rower)
Coxed Four (4+) - 5 persons (1 oar per rower) 4 rowers + a coxed a small person normally slows boat down but does the steering.
Octuple (8x+) - 9 persons (2 oars per rower) 8 rowers + a cox
Eight (8+) - 9 persons (1 oar per rower) 8 rowers + a cox
The PB over segments is really good but if you go out in different boats the PB's don't fit as you need a different one for each type of boat as each boat will be different in speed. It would be really great to be able to select the type of boat when you select rowing and so PB's are separated or indicated based on type of boat.
You have a tick box for indoor rowing, maybe something to indicate a boat type and so different boats can be highlighted in PB's? There might have to be a limit on the number of different teams/crews say two so normal bike and tandem. But even that would give the option for people to separate out individual PB's and Team PB's