jaf via Plone Community wrote at 2022-6-2 20:08 +0000:
...
- Is there a relatively easy upgrade path for a Zope 2 application to Zope 4 and/or Zope 5
There is.
- Is Plone a well suited for building web-based, relational database records management systems?
That is not Plone's primary purpose.
If you need nothing else, you likely do not need Plone.
A client (with essential data in an RDBMS) is using Plone
because he provides so called "business portals" (over 1.000)
for his clients and Plone has good support for customizable
portals, portlets, limited customer content, workflows, customizable
UI facilities (e.g. Action's).