You brought up T+3 which is going to T+2 in September but will still be way way too slow. If regulators were to implement T+0 or same day clearing it would eliminate much of the fraud in our markets including abusive naked shorting.
Yes it can be done and has just become available thanks to Patrick Byrne.
If this gains traction and attracts increasing numbers of companies that do not want their stock attacked nor their shareholders abused it could force other markets to operate similarly imo. Some will find this interesting. Go IPIX!!!
https://tzero.com/