Unlike 32-bit or 64-bit, it's harder to check actual CPU instruction compatibility of the app or OS.
For what it's worth: I never ran into this problem with different older laptops. If you do, maybe
Gentoo will work if you just compile the entire OS without that CPU instruction.
Since it's not mentioned yet, you can enter your own or custom entropy when using iancoleman. Just tick/click "Show entropy details", choose the format (such as hex, binary or even dice) and enter the entropy on the text box.
The reason I'd prefer to do this manually, is that I don't want to trust Ian's software to really use my own entropy. A compromised version of the software could just produce a predefined key. If I flip coins or throw dice, I want to be able to manually
verify my seed phrase is made out of this.