Performance Problem with smart_date_recur_entity_delete

Problem/Motivation

Currently I have hundreds of nodes (type event) using the smart_date_recur dates.
This type of nodes is automatically imported and cleaned via cron-jobs.
Currently i have the problem, when deleting multiple events (~50) or even a single node of type event, it iterates each time over all entries in the smart_date_rules (~80000 entries).
This is taking too much time and results in a timeout.

Steps to reproduce

Large amount of smart_date_rule entries in the db.

Proposed resolution

is there a better way to get all the matching rules from the current deleting node? as iterating over all entries?
Maybe storing the node-id also on the smart_date_rule?

Remaining tasks

User interface changes

API changes

Data model changes