When I worked (I)PM at the distillation farm, they put Silica into the hydro mix to try and combat... well every single cannabis pest imaginable. Their grows were huge 30' tall hoop houses with concrete floors that each held about 10k veg plants and 5k flower plants give or take. Used to be some kind of flower nursery 50 years ago. They could have leveled the houses and gotten better results outdoors.
Each house had a huge wet wall that they used to try and control the temps and keep it under 100°F, one day they got conditions perfect and made it rain, indoors. That was so depressingly funny to watch it rain on an 'indoorish' grow. They used paper 'fins' in the wet walls, which you could see through outside onto the property. When construction kicked up next door, they were blowing dirt loaded with all kinds of crap all over the flowers through wet walls. So there was absolutely zero pest prevention in the infrastructure, I argued we encouraged pests and then they couldn't get out because of the wet wall fans, kind of like a hotel California for bugs, check in for life. The humidity was insane, and the temps would routinely climb above 115°F in the summer and the 90's in the winter. Si was their holy grail - hail marry attempt to try and save us from Bhang Cannabis aphids, root aphids, spider mites, thrips, caterpillars, you name it we had it in at least one house.
Their results... there was a slight-ish reduction of pests, it was far from a save all, but the buds stood up proudly as they molded and died under the bug and dirt filth. No real change in WPM or other molds, those were very happy molds and fungi no matter what we did. Once we hit week 3 of flower there was very little we were allowed to spray, so from there it was war between the benificials and resident bugs.
Personally being part of the syn-ganic cult, I use Chiten and Chitsoin (ground up seashells soaked in acid until it's soluable for the roots) so I don't have to tie up my branches as early. The theory is essentially the same as Si, the Chiten and Chitosin build up in the tissues and makes them stronger and more difficult for bugs to eat.
The biggest benifit you'll probably see will be stronger branches to hold up the buds. When they started using silica I had to get a ladder to see the mold on the buds, before silica they'd fall over far enough I didn't need the ladder.
