As this new functionality in 8.0 is intended to set a fixed time limit on all nodes across the cluster.
Is there a possibility to set it different for each node?

Our non-operational (Analytics) or secondaries may be capable to tolerate higher limits than Primary.
Yes, 'maxTimeMS()' would overwrite this but adding it to all the queries is not feasible & occasionally the same deployed query may need to run little longer to retrieve/scan more docs than it was originally supposed to.