I am not sure the Hapax does the same workflow as the Deluge, what makes you think that?
Hapax has a Live and Step mode, which interact but approach things differently. I watched some Deluge videos earlier out of interest and it looks like there is just one grid mode which sort of combines both of those things.
I’m not saying that your idea isn’t valid, but it seems that the workflows are different. And for the record, I don’t consider pressing a button to audition notes a ‘workaround’ more than ‘how it works for this sequencer’
Again, I’m not having a go, but different machines are always going to work in different ways, it’s essentially up to the people who make them how they want them to work.