one of the beauties of SOLASTA is its attempts to be true to 5e and I am very happy they are making attempts in that direction, that being said, there might be a bit of implementation that needs ironing out. i think one area that irritates some people is how it is ok to "ignore" somatic but then others situations you can't ignore them. there are spells that allow you not worry about somatic/material components in a special but very common way, that is holy symbol on the shield of a cleric/paladin. that i think is where the confusion and then becoming too lax with rules sets in.
i'm going on about a month of bad memory but i'm not sure if SOLASTA is catching all of the nuances of VSM components. for example here is nice summary for clerics [paladins]
reddit review of sage advice CluelessMonger says
"It's the same rule as always. Only somatic? Need a free hand to wave around. Only material? Need a free hand to grab the material. Somatic and material? Need a free hand, but the same hand can be used for grabbing and waving.
Since the shield-symbol replaces the material component, you use the same hand (shield hand) for grabbing and waving. If the shield-symbol isn't part of the spell component, a completely free hand is needed to perform the gestures."
so if SOLASTA is accurately capturing all of the subtleties with casting and holding items i think the default should be 5e RAW, especially since SOLASTA is overly generous with the switching of items during combat, although i don't remember if there is free drop option, even though there is not technically a drop item free action.