Hi,
P1: I am 5"8 now
P2: Really so you topped me i'm 5"7
Or
P1: I weigh 56 kg now
P2: Really? so you topped me i'm 54 kg
Thanks
Yes, "topped" can be used in this context.
You can, but a sensitive and particular reader would find them a little out of place, given that topping someone is, in such a context, associated with a performance, rather than a competence, or particularly, an unalterable trait.
You can top me in the long jump one day, and I'll beat you another day. For me, height is not usually seen as that sort of a performance. I think I'm right in saying that.
See definition #5, transitive verb. top - Definition of top at YourDictionary.com
The fish is topping a weight, not another fish; if it were to top another fish, it would probably be in an angling competition.
I agree with konungursvia - "You can, but a sensitive and particular reader would find them a little out of place", except that I don't think the reader has to be very sensitive or particular to find them out of place.