For a 'Show HN', no registration is better for me because I'm just going to put in a fake address and a guessable password anyway...if I bother to provide anything at all.

I'd put it this way, 'Show HN' is a good potential way to get feedback on the implementation and idea for the purpose of improving the project/product. There's a lot of expertise here.

On the other hand, for most projects it is probably about average in terms of garnering emails and page views. PR and marketing aren't going to do better.

Finally, in terms of the project, it looks like something I'd expect to see as open source rather than a product/company. It's cool and potentially useful and if it were rolled into an IDE or an editor it could be a great feature.

But it's harder to see how much I would gain by a business commitment. Collaboration means convincing other people to try it, hoping they find it useful, and then learning how to coordinate use.