According to Open Frames standard: https://github.com/open-frames/standard farcaster properties are compatible with Open Frames properties, but frames.js debugger is not rendering fc:frame:buttons when using XMTP mode. 

@df

Building open source via @frames, /open-frames to help Farcaster and decentralized social win. a16z CSX23. Side projects: farcasterchannels.com farcaster.id

I’m a builder looking for the next challenge. 

For now I just copy the buttons and change the naming.

the properties are the same but the naming is slightly different; xmtp uses of: instead of fc:frame: and there are some slight nuanced differences as well