The TimeScale licensing approach, the way it is written, perhaps accidentally, has lots of hidden landmines. The TimeScale license slants toward cloud giant defense to the extent that normal use is perilous.
For example, timescale can be used for normal data (postgres) as well, so any rules seem to apply to all your data in the database. The free license only usable available if:
the customer is prohibited, either contractually or technically, from defining, redefining, or modifying the database schema or other structural aspects of database objects, such as through use of the Timescale Data Definition Interfaces, in a Timescale Database utilized by such Value Added Products or Services.
My read is that if you let a customer do anything that adds a custom field, or table, or database, or trigger, or anything that is "structural" (even in the regular relational stuff) anywhere in your database (metrics or not), you are in violation. There doesn't seem to be a distinction about whether this is "direct" control or not, or whether a setting indirectly adds a trigger. I don't want to be in a courtroom debating whether a new metric is a "structural change!"
Now, none of that might be the intent of the license, but you have to go by what it says, not intentions.
The sad part of that is, I, and I'm sure many folks, have no interest in starting a database company, but we can't rally timescale because of legal risk. Looks awesome otherwise, though.