The thing is: why should I spend 40€ without knowing if I'll have TRIM, if I can spend 25 for a 16GB SD card and a good usb3 adapter?If I was certain to have TRIM them 15€ can be worth, otherwise is just complicate things
You have an Asrock H170M Pro4S logic board so you have a free M.2 PCIe slot don't you ?
If you want something cheap and reliable why don't you buy a 16 GB Intel Optane SSD ?
Those SSD were expensive but can be found new for ~20€ and have both an excellent endurance and reliability.
A 16 GB Optane M10 SSD has a 395TBW lifespan while cheap 120GB SSD only have 40TBW lifespan...
I can testify that a 16GB boot drive for OMV is a good choice : those devices are fast and ultra reliable, they make a perfect choice for OMV.
Also I like a lot the fact that, once selected as a boot device, any NVMe device (as the octane) will always stay the first boot device.
If you manage many SATA drive and have one as your boot device you can be annoyed with the wrong drive being selected as boot device and your OMV machine not booting...