I'm not clear from your comment whether HCE means I could in fact use it for PayWave (rather than just PayPass), despite the title? Would it work with Opal too for instance?
I haven't tried myself (I have PayWave, and this is now on my todo list for tomorrow), but I imagine that they maybe hadn't tested it on Paywave when they wrote the title?
The standard(s) seem pretty pervasive, and I've often had PayWave work where there is only a PayPass sign...
On your last question - I'm not familiar with Opal at all. Any links/information?