SSD Write cache

I’m getting a little frustrated with the slow writing speeds of my ‘my cloud ex2 ultra 8TB’. I’m not really interested in buying/building something else, although my Linux experience has come a long way since when I bought it in 2017.
Anyway, I was doing some research, and apparently it should be possible to create a read/write cache using dm-cache or bcache (available trough Entware), and an external USB SSD. I’m not sure if this would be a good idea. I don’t want to mess with it too much, because I do not have the storage to backup 8TB of data.
Has anyone tried this? Would this be a good idea? I have some SATA/USB adaptors laying around, as well as a Crucial BX500 SSD.
I’m mainly using this for direct playing files with Plex and downloading ISO’s with Transmission. It is a pain to upload files as the write speed drops to 0 after 100MB or so, and Transmission gets stuck on ‘flushing files to disk’ or something like that.

Hi @freddo256

Have you checked our knowledge base articles?
(Support for Western Digital Hard Drives | Western Digital)

Have you opened a Support Case?
If not, contact Western Digital Technical Support for assistance.
(Contact Us | Western Digital)

Hello @kumburle.pradeep
Yes, but there isn’t anything useful there on this topic.