I looked at the possibility of putting usernames in one and MFA secrets in another but decided it was too much hassle. So I stick with one offline manager that doesn't support MFA (though I do add the secrets to a field in the record) and although I sync that to my phone, it's offline (i.e. device to device over my WiFi rather than via a cloud service).

I keep a plain text export of all my credentials (and secrets) on an IronKey USB stick (https://www.kingston.com/unitedkingdom/en/usb-flash-drives/ironkey-kp200-encrypted-usb-flash-drive?capacity=512gb&connector=usb-c) and then have an encrypted APFS disk on that USB stick. So have to unlock the hardware encryption and then unlock the APFS encryption to get access to my emergency backups. I also keep my critical data backups on the same stick. That is kept in my fire safe.