I guess everyone will have their own opinion on how to handle TRIM, but I suggest enabling it unless you have issues with your specific SSD with TRIM enabled, then disable it.
I have only seen one or two threads about drives acting screwy with TRIM enabled, so chances of this happening is pretty slim I bet.
The benefits of having TRIM enabled on the OS level would be worth enabling it, if it currently isn't.
Is there a way to check whether TRIM is enabled in Terminal?
You can see it with the GUI in the built-in System Information app, otherwise known as System Report.
The app itself looks a little different depending on the OS you are using, but pretty much the same general layout for the last 15 years.
If you are using a NVMe SSD, then click NVMe on the left hand side column, and click on your drive from the device tree if it is not already selected, and go down to TRIM Support. If it says "Yes", then TRIM is enabled. If "No", then it is not.
With the later APFS-based version of macOS, however, will TRIM be enabled on SSDs automatically?
I'm about 90% sure that I had to enable it manually on a 2014 Mini,
I could be wrong, but in my experience, if the Mac came with a SSD, either pure or in a Fusion Drive set up, then TRIM is automatically enabled.
For any Mac that only shipped with just a HDD, TRIM is automatically disabled, and you can easily enable it using Terminal.
It only takes a few seconds, and just copy and past in the command.