HM and Blackwater vault hardly ever get triggered and most people do area 51's as it is the main source of money for big gangs.
I would like suggest that when you rob HM and BW Vault you get more money than area 51 so people actually rob these because at the moment there pointless.
These are some points i have thought of:
Move Gold Trader closer to HM
Make gold spawn in instantly. Instead of having to wait until the end of restart to get the most money
Increase money for selling both gold bar and counterfeit cash
Change the counterfeit cash location as its in a town and its pretty boring to fight and travel
Change the compounds around abit to make it new and different from before
If you have any other ideas go ahead and put them in the replies. These are only ideas as no one does these majors and something needs changed