+1
Realistically, cops would definitely catch on when people deposit or make a lot of money like when they process their drugs or sell their drugs. Having ways to explain it with legitimate businesses like gun stores, clothing stores, etc would be cool and brings more risk when you're doing high profile stuff that gives you a lot of money (trade/crew deals, selling class 4 guns). Right now the only way for cops to really tap into the criminal world is just through being an undercover agent and that's mainly detectives only, adding this brings more criminal and cop rp. Could maybe have a separate division like IA to investigate suspicious withdraws or deposits.
Honestly this could tie into the briefcases suggestion. There will be a max amount of cash you can carry in your wallet so people don't avoid the update entirely by just not depositing anything, but you can also fill briefcases with money and put them in your bank for big cash deals. Briefcases are limited though so you won't be able to fill much, maybe around $25,000 with the cost of the briefcase costing $5,000? If you want to fill higher amounts, you either have to
a) upgrade the briefcase with some npcs that trade, into an upgraded briefcase which can carry $50,000
b) buy a duffle bag from barge or sewer npc which can carry $250,000 but is risky as it can show up on your back when carrying it at full/near full amount as well as showing "carrying a large sum of money" red text kind of similar to the package event thing