Its a load of crap man.
Educate yourself on what self custody is.
It isn't a secure element...
Discussion
What is your solution to self custody?
I don't store my seeds on digital hardware.
I only store my seeds on steel.
How you generate those seeds is up to you, but I use the bip39 word list printed out & cut up in a jar, mixed up & randomly picked.
Then use your preferred HWW to generate & export the xpub, I prefer a seedsigner that you build yourself.
If I use a HWW that stores the seed, like the CuckCard, I wipe the device after this process is done.
I import the seed when a TX needs to be signed.