Mine is Multi Edition.
...
Why is it good to convert it into Bitcoin-only?
Oh really, so you are telling me that you purchased Bitbox hardware wallet.
Would you be so kind of taking a picture with this device next to the paper with today date and your username written?
You don't have to reveal any other personal information, images or wallet address, just device + paper with date/username.
Thank you.
If you are using shitcoins you obviously won't install Bitcoin-only firmware, but that makes code much bigger and with much more potential bugs and exploits.
I didn't hear a single case of someone losing coins for installing multi-coin firmware, but it's always possible to happen in future.
Smaller compact code = less potential bugs and exploits.