ZWSP or ZWNBSP between emojis
I tried adding a ZWNBSP (zero-width non-breaking space http://www.unicode-symbol.com/u/FEFF.html) between custom emojis to see how it would affect the way they rendered. On pleroma, separating emojis by ZWNBSP doesn't seem to affect the way they're rendered, but the same post viewed from mastodon gets totally different treatment.
If you post emojis from pleroma without any spaces between them, they unfortunately show up like this when they get to mastodon:
That software just can't handle emojis without spaces for who knows why. And they don't plan on fixing it, afaict. Someone submitted an issue a long time ago, and it got closed as "inactionable" or something.
Well anyway, here's the same message, but with ZWNBSPs in between the emojis:
And here it is with ZWSPs (http://www.unicode-symbol.com/u/200B.html):
Idk which would be preferable between ZWSP and ZWNBSP, but either one seems to make unspaced emojis work on masto, and neither seems to mess anything up pleroma-side (although pleroma itself doesn't need them at all, just as masto shouldn't need them). Maybe when pleroma sends mastodon an unspaced emoji, it should automatically insert a ZWSP. Or something. Idk. Basically, ZWSP makes it work.