I am using a 1TB Samsung T7 external SSD and tested the SSD and got about 350 mb/s. The SSD is connected to the blue USB port in the pi 4. Btw I am using Bullseye as per the guide. Apparently tried with Bookworm and there were permission issues that I couldn't resolve.
You can run into an issue, when your SSD demands too much power from the Raspi 4B. A Raspi 4B can only provide a total power budget of 1.2A@5V (or 6W) for all its USB ports combined! Not exactly sure about the Samsung T7, it will mostly work but maybe can overwhelm the Raspi.
With only 4GB of RAM you will later in IBD run into I/O intense periods when chainstate grows way larger than 4GB and you can't give sufficient RAM to dbcache (see below).
The OS shouldn't be much of a factor here.
From an own full IBD experiment started somewhere in June 2023 with an Umbrel node that only ran a Bitcoin Core container via Tor on a Raspi 4B with 8GB RAM and a 1TB SATA SSD connected with an USB3-to-SATA adapter, I experienced a full IBD within about 95h until full sync with
onlynet=onion, onlynet=i2p basically (I also had a setting of
dbcache=4883 in my node settings).
Your IBD will be slower as you can't reserve much more than maybe 2 or 2.5GB to dbcache. During IBD you may consider to set
blocksonly=1 to avoid having to verify possibly incoming transactions.