FSTRIM for USB-SSD boot drive

I would put my Ubuntu 22.04 NVME disk into this USB 3.2 20Gbps M.2 NVMe SSD Enclosure and boot it from a USB 3.2x2 port. I know that a SSD needs to be trimmed by FSTRIM, but I also read that accomplish this, through an external USB enclosure, should be a trivial task. In this old post the above topic has been already discussed, and somebody suggested to rely on the UDEV rules, as explained here . My questions are: 1. Could the above UDEV approach work? 2. Could the UDEV rule work for a USB boot SSD too? 3. A friend of mine boots his Ubuntu OS by a UGREEN enclosure, regardless of the TRIM. What could happen to the SSD if we don't care of the trimming? 4. If trimming over USB will not be allowed (is it harmful?), why SSD enclosures exist on the market? Thank you in advance!