I don’t see the point in restricting any potion weights. Masked scent is not trivial to make, if people really manage to do and keep 100 on their belt why not. Currently they CAN keep 30 there or more already and if those are gone - if they really happen to have 100s - the only thing needed is go back and stock up.
Same with speed, if someone is able to burn 30 speed potions in a row that is already a huge advantage in pvp, nothing really changes much if it’s 100 instead, except of not having to run back to the house two times in between. And then it likely takes full days to fish and craft new ones, so, probably 0.1% of players would even consider using that many on one take.
As for pve I frequently forget my fishing potions wasting reagents to port back to the house, would love to have a few in inventory, constantly. All that this would do is save me running and allow to go fishing, spontaneously. Ithecac weight is already changed and it feels great to use them anytime in the world if you feel like it and see something interesting.
The advantage of having more boosting potions than I need, personally, would be the possibility of helping others out in dungeons. A frequent argument to stop hard raids or boss-tries early was everyones potions ran out I don’t see why that must be so.
The next advantage is the one for sellers and buyers carrying potions. If you plan to buy a stack or more from the outside-auction house in HS right now, then better have your portstone ready…