>>396114661
>>396115990
I think it's fine as it is without an extend button and that adding it would dilute the core mechanism of speed- (!) dating.

The rare coin idea goes in a better direction, because then the question of whether the interlocutor will extend is more in the background, with it being the exception, but I still find it to be worse than just there NOT being an extend function.

But, hey, it may even be a welcome surprise that the interlocutor extended, so you can continue to have fun. It'd make you feel good that the other person is willing to spend the rare resource on you. 
On the other hand, someone may feel bad that a good friend or interesting partner isn't willing to spend the rare resource to get more time with him. 
Furthermore, think about this situation: What if you _don't_ want to extend, but the other party does? Oh no, another 5 minutes forced into this horror conversation? Will you respawn and doubly hurt them to get out of it, after they were willing to drop their coins on you? I guess a rejected extension could be refunded, but will you bear another 5 minutes of torture? It's just 5 minutes, after all, but you could've spent that with someone new. 
Also, will both people have to agree to spend coins? Will you make people have to lie to the other person that they don't have coins to extend when they do? Will it be only on one person to spend the coins? If so, who would pay the "tip"?

And all of that just to preserve a conversation you could've just left open-ended, so you'd have a conversation starter for the next time and another reason to join on the new friend you made.

Less relevantly, because we don't have world persistence yet, it may also be annoying to lose your coins accumulated over 3 hours because you got disconnected by your internet provider or crashed by rando tourists like that micspamming ban-evader and their orbiters, who both were there yesterday, and the kind of which we'll always have to deal with.