With the price of SSDs nowadays and the small capacity of the unit you’re looking at, it would be remiss of me not to bring it up.
A 1 TB MX500 is only ~100 Euros and should be received as a great QoL upgrade, especially so if the external drive is something that is borne out of necessity and not a specific plan to keep some files elsewhere.
Perhaps worth mentioning that inexpensive SSDs don’t like to be very full (wear leveling as well as other reasons) and their theoretical endurance also drops precipitously for smaller capacities.
IIRC for larger units it’s generally recommended to keep free space around ~15%, at either of the spectrum, however, absolute figures might be more appropriate than relative, though.
For the average unit that doesn’t develop faults this is likely a relatively insignificant concern, however you never know if you’ve lost the lottery until later.