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Yes, the big ones do: palnet, creativecoin, photostreem, neoxian. You don't have to use the interfaces for posting but if you use use the tags when posting on steem and you have coins staked, you can give and get rewards in those coins. If you go to each frontend, find your steemit profile and log in with your posting key

Excuse the spying but your wallet is here https://steem-engine.com/?p=balances&a=irreverent-dan and I see you have PHOTO and PHOTOM which you really should stake, since that is your thing.
The PHOTOM is a miner token and will give you passive earnings. The PHOTO will give you VP when staked.

Thanks Nikv! I managed to stake the PHOTO & PHOTOM tokens, but then I got an error message from SteemConnect - a tool that I find frustrating.

You don't have to use the interfaces for posting but if you use use the tags when posting on steem and you have coins staked, you can give and get rewards in those coins.

This clears my confusion. I thought the dedicated interface must be used in order to utilize a token.

Happy, to help:)
Yes, steemconnect is a pain. Keychain works much better. Apparently the PHOTO coins just work with the #photography tag, there's no need to use #photostreem for that

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