It appears the throat could be opened up some...what you have now seems as though it will support low lift low speed air and flow good numbers however once the lift and therefore velocity increases the air will have a hard time sticking to the tight turn all the way throughout the SS and will separate and become turbulent. The throat could be opened some but you need to be careful...too much and it will kill low lift. Also as you open the throat you are decreasing the angle of the SSR effectively moving your separation problem to the point now where the air coming down the port reaches it highest speed right at the apex of the turn. So this area needs to be contoured carefully...and there is water in it too so it gets tricky...if you can't get it where it needs to be then sometimes it's better to leave it a little sharp as air can't really notice a a difference of about less than a 15 degree divergence. So if you try to get it too radius end you may just hit water....get it close...and if you have too you might be able to widen the floor here to help slow down the air...but be careful as you can start trying to force the air where it doesn't want to go if you aren't careful and then things get turbulent ...That is the reason I don't like the guide vane bias....and there is still the water issue....
Most low lift flow is in the area right around the seat....mid range numbers are in the SSR and the high numbers are influenced by chamber, SSR and other areas of the port...but these are just very basic generalizations....air does not like to turn....but if it does it doesn't know much difference between beyond 15 degrees....it also doesn't like to expand....but if you make it smaller then it gets faster and then it wants to go straight....again...VERY basic generalizations....and little changes at one place can make big differences somewhere else....
If they were mine I would open the chamber wall and unshroud them a little, work the SSR and open the throats a little bit....that is the intake side......exhausts are another story......
Ask 10 other people you will get 10 other answers....