Its a much better deal than the A71, 7000mah battery for essentially the same phone and almost £100 cheaper yet the only place i have seen it for sale is on Samsung UK website, Its like it does not exist, even sammobile has no firmware for it and I have never seen that before on Sammobile
There is a few online sites that also sell that phone model @dj1891
I guess businesses will only supply a phone they think that will sell well !
I'm not sure with custom roms and I assume its the same situation. There maybe more info on xdadevelopers.com.
Are you tempted to buy the phone from Samsung UK Online ?
They may also be available in a Samsung Experience Store if you have one local.
Current Phone ~
Samsung Note 20 Ultra 5G SM-N9860_256Gb SnapDragon 865+
Samsung One Ui 3.1/ Android 11.