There were lots of reports of external HDD causing issues, in fact I had such issues (locked up and had to rebuild the database) so unplugged and haven't used since...has that issue been resolved?
I bought a Crucial X8 2TB and had tons of problems to begin with.
1. Unable to format the X8 drive with the PS5
2. Formated the drive on my old PS4 Pro, but still not able to move files to the X8 ssd with the PS5. (PS4 games on internal SSD to external X8) This also caused my PS5 not to properly go into rest mode and I had to disconnect the power and then rebuild db on the PS5.
3. After formating again on the PS4 Pro and moving a couple of games from the PS4 Pro HDD to the X8, I could also move games from internal ssd to the X8 on the PS5. Now rest mode works fine also.
Go figure!
As for new firmwares it has been xmas, and probably not much work was done over the holidays and did they not release on just before? Without knowing how much work and qa time they use, I am guessing we will see one in februar.
//EDIT
Oh yeah, Crucial support was useless, one agent disconnected me from the chat after a couple minutes.
The second agent dangled me along for 20 minutes and sent me link to a PS4 guide even tough I explicitly wrote PS5 etc. After 20 minutes, where the agent probably managed to send me 5-6 messages. They refered me to something else and that I would be contacted within 24 hours. Its been 4 days or something. I was pissed about being disconnected the first time, so kept saving the log and nagged the support agent the whole time, took 20 min before they gave up (I was always nice and polite, its not the agents fault they have had sucky training)
So unless you confident that what you want to do and that it works for certain. I would give Crucial a wide berth.