Also with the M1 Pro MacBook, my LG USB-C monitor broke during the upgrade. Black screen, same on another connected USB-C laptop. Tried different cables, unplugging power from the monitor and factory reset on the monitor, no luck. Other inputs like HDMI and DisplayPort still work. I don't think the breakage during the upgrade is a coincidence.
I would really advise against having anything connected to the Macbook during upgrades, except the charger...
One approach that can be used is to use the centralized service to answer a broader question like: given this user, what rules can I use to know if a document is accessible for them. And have the service give you a set of rules to apply. Then take the result and embed those restrictions in your query.
An example access service response would be: this user can access data from groups they are part of + documents for which a share exists towards this user + documents for which a share exists to any of the users' groups.
This is not exactly the same as the first option you described, because instead of storing access controls in the index data, you use the available metadata + the rules from the access control service.
I would really advise against having anything connected to the Macbook during upgrades, except the charger...