Polymorphism would be nice: a way to join tables with common columns under a parent or generalized table

[louca.developer]

This is now possible with the Merge Table pack:

Launched: Merge Table Pack

The Merge Table pack enables merging and syncing multiple tables across docs into one combined sync table. Similar to the Cross-doc pack, but with the added benefit of being able to pull in rows from multiple tables at once to merge their values under common columns! Useful for combining multiple tables that share common columns, for example merging Tasks, Meetings, and Projects tables into a single Calendar layout table showing the names, type, and relevant dates for each. See the pack listin…