I think it all depends on what plants you are planning to plant in your tank and how you want them to look/grow.
IMO most stem plants only need a little off the bottom and the roots trimmed if any.
I have Ludwigia Peruensis and it grew vertical very fast with out trimming the tops off to start. Once I trimmed it it started growing new leaves (next to the old) and 1-3 new stems/plants near the top where I trimmed it.
All in all it depends how you want it to look. But I guess sooner or later you will have to trim and a certain look will have to be tolerated to a point.
Hope that helps
IMO most stem plants only need a little off the bottom and the roots trimmed if any.
I have Ludwigia Peruensis and it grew vertical very fast with out trimming the tops off to start. Once I trimmed it it started growing new leaves (next to the old) and 1-3 new stems/plants near the top where I trimmed it.
All in all it depends how you want it to look. But I guess sooner or later you will have to trim and a certain look will have to be tolerated to a point.
Hope that helps