I think if you should put this - you should also pull in the value of org-roam-db-gc-threshold here its value is set to 8mb by default but this was created for org-roam to get temporary gc limit boosts - documentation should also state to push it to 16mb or somewhere around there to get the benefits.
This will extend the GC threshold for the query and will let your cons function shine through and show its effect more prominently – it will be non intrusive too because the variable is already defined in org-roam.
I think if a custom cons function is present and formatted correctly it should also hint to the user that they may choose to not fill all the details - but for api reasons we need to fill all the slots - I think with the GC value pulled here with ample documentation - this makes perfect sense.