As nicely as this avocado tree is growing, it does need to be prompted to start branching out at some point.
If I prune off those top baby leaves and leave the two nodes intact, will it start branching from both, or only one?
Current height is around 14 inches tall.
Eh it depends. Generally both will branch out!
If you find only one node sprouting out - trim that one back until you get two (or multiple nodes) all sprouting at once
If you let the node keep branching and growing solo then it will be harder to cut it back later and let multiple nodes take its place. Or the ‘stunted’ node will just never grow, the stronger one will take priority
For stronger stem get a fan, some gentle swaying will beef it right up!