Similar to the local block-autoblock-exemptionlist for local blocks, it should be possible to prevent global autoblocks on a configurable list of IP addresses.
This list should be global and definable such that it can be modified on wiki without the need to modify site config.
Global autoblocks should also potentially respect the local wiki's autoblock exempt list, such that they are disabled on that wiki if listed at MediaWiki:block-autoblock-exemptionlist).