It is a little harder with aluminums because there isn't a big selection of heavy inserts for the sizes.
I don't know of any steel inserts.There are only 3 sizes of brass inserts for aluminum-2016,2117 and 2315/2317.
2016 are .531 deflection,2117 are .407.I'm not sure if 2117 would be quite stiff enough for a 100 gr weight increase.It might be if it could be cut shorter than your 2016's.
It could be done with the 2315's which I believe are 340 spine but I'm not a fan of that fat a shaft as it will slow penetration compared to the thinner ones.
A really good shaft and tough,is the 2020.You can modify the 100 gr brass insert to fit in it.You screw a field point into the insert.Chuck the field point into a drill or drill press.While it is spinning,use a mill file to reduce the shank of the brass insert.Stop the drill occassionally and test the diameter with a piece of shaft.It will probably end up at app. 90 grs which probably would be very close.
The easiest way to increase the front end weight would be to get a different broadhead-a glue on,and use either a 75,100 or 125 gr steel broadhead adaptor,in conjunction with the standard aluminum insert.
I would get 2020 shafts and shoot a variety of point weights till I found out which they liked,then pick a glue on broadhead that would give me that weight when combined with the right weight steel adapter.
Like I said,the other option is to reduce the 2016 brass insert.I have done this with 2018's.It takes a couple minutes per insert.You still don't know exactly the proper head weight till you shoot them though.