As it stands now, there's a number of legacy systems that still correlate your PC $Name as a means of identification and some newer ones which use SIC. With the recent adjustment to SIC ripping and what I perceive as a roadmap to resolving these discrepancies - I propose the following:
The majority of city-specific accessible systems should be SIC driven. The exception being those systems that are widely spread across the globe such as vehicles, banking, etc. These systems should rely on biometrics I.E. when you see Takeshi Kovacs spit blood on the Hotel Terminal in Altered Carbon or when Delores takes blood from an unexpecting corpie in Westworld to trick a bank transfer.
The promotion of both biometric and SIC means of security bypasses would create new avenues of "cracking" that involve doctors and techs.
Ideally, we would be creating multiple factors of authentication for system with these two being the backbone.