Im not sure so much about the other coins. Also, it's made more complicated because a lot trade against BTC, which relatively unstable.

What I would say that bitcoin is the best one for triangle pattterns. But as we saw there, we got a nice one in this instance for ethereum too. Not sure about the others, but I guess you might find them in some instances for the likes of Litecoin, Monero, Dash, etc....but I don't really know as I don't trade these much. So probably BCH might be similar. But I have definitely seen them sometimes on poloniex even trading against BTC, but it's more random I think.

However, what I would say is EMA crossovers and MACD crossovers apply very well to any coin (privided not really low volume) in my experience. So I would probably look to these indicators more than triangles for these other coins.