I'm managing the crazy signups as an example of how this might be done with custom html pages. github 
We now have a workable Register plugin supporting the simplest "friends" workflows. We now consider how we might handle more nuanced situations without stumbling as we have in past proposals.
home
To enable this demo variation of custom registration requires at least three changes.
● Move register.js to the server's status directory.
● Move index.html to the custom "home" asset folder.
● Upgrade the Register plugin to version 0.5.0-pre3.
wiki-plugin-register
# Demo
We have just enough custom logic working that one can enter an email and have it saved so long as nothing goes wrong. In step 1 you will enter a possibly fake email address. In step 2 you will see that it has been recorded.
Step 1: visit the custom home page. Enter an email address and the press ok. Come back here for step 2.
Step 2: Retrieve all recorded emails in another script designed for this purpose.
Since the GET endpoint returns a list of signups, we can call that directly from a wiki Frame. We expect this to eventually require admin access but for now it is harmlessly open.
http://crazy.fed.wiki/plugin/register/custom HEIGHT 200
Tip: jiggle this Frame to refresh with recent signups.
Tip: import file system apis to provision sites. node
Tip: use ssh credentials to deploy register.js.
ssh asia 'cd .wiki/crazy.fed.wiki; cp assets/home/register.js status'