Nutrients : Same as usual , it is still a plant even if it's a weird plant so sane feeding than a regular one and go like that until the end except if a problem accrues ( over or under feeding ) and in that case you can easily do the balance.
No need to top now as the 2 top leaves will help for photosynthesis so just wait for the 2 stems to be well developed before considering cutting them.
No need to LST now but it will be a good option as you will have 2 sides with that 2 stems so maybe you will bend them ro help building a shape.
Btw it is a genetic "issue" mostly weird that will maybe slow a bit the grow but nothing harmful
Hey!
It is kind of normal to have some little mutations on the first stages of growth. Just let her grow and probably you will notice that she recovers by itself.
@AsNoriu Hi mate I one similiar to that a little while back What happened with mine was the plant formed two new branches beneath that top and then
they grow out to become the new tops leaving the mutated top behind . I still got the exact same smoke off that plant as I did its normal looking sister
Nutes will be the same as any grow