if a full int does 10 phy dmg, he can do 100 with imbue
if a full str does 90 phy dmg, he can do 100 with imbue
just an example with random numbers.... (i dont think a full int and a str would do the same dmg)
now ur a full str, what u want to do, 90 dmg or 100 ?
lvling imbues allows u to add a bit more dmg to your weapon skills, even if for a full str is not as much as for a full int
if ur question is: is it worth spending sp to get an imbue for a full str?
it has a more complicated answer imo.... but it seems that everyone uses it... i guess because no one wants to have only 1 mastery and because of all the guides and because i assume ppl have learnt from trial and error
maybe you can try a full str without imbues, and then u can tell us
