Some of the chosen emojis don't render on all major platforms.

[goodevilgenius]

I've seen some sets with 🕁.

On my Android device, this renders fine. It appears to be a medieval cross with a half circle below.

But, on my MacBook, this renders improperly:

Since my MacBook is fully up-to-date with the most recent version of macOS (Venture 13.5.2), it seems odd that an emoji would be chosen that would be able to be rendered on an recent Apple device.

[mapmeld]

I did a little investigation last week and these boxes "remain part of Unicode, but are not recommended to be included as emojis": https://emojipedia.org/unicode-7.0
It would be possible to replace these with newer emojis released since the original what3emojis release