I have invested some significant effort over previous weeks into making Mockup 2 work nicely with plone.app.widgets 1.x on Plone 4.3. I have two open PRs that I would like to see reviewed soon, and I think the work invested here is justifying a new release of plone.app.widgets 1.x (as 1.9.1).
Here are the particulars:
Numerous compatibility fixes and improvements:
Make static text portlet on Plone 4 use AutoExtensibleForm, which means TinyMCE from plone.app.widgets will actually work for that portlet:
This ought to make widgets on Plone 4 very close to Plone 5 -- IMHO, a big win for folks either trying to transition to Plone 5 incrementally or folks stuck on Plone 4 for a while.