Let me start by saying that you don't have to be a developer to use the Developer Edition, and I highly recommend going that route to anyone who can. I run it on a regular Windows 10 PC that has IIS turned on. It takes a bit more time than the AGOL version to implement the upgrades, but not much if you don't use any custom widgets. So far, installing a new version has merely involved downloading and unzipping a file and running a couple of commands in the command window. If you don't have any custom widgets, migrating to the new version would just be copying and pasting folders from a single location. You would then have to download and unzip ExB files to your own web server to replace the older version there too. This puts you in control of all updates to your ExB apps!
The Developer Edition would allow you to use the Print Widget that you referred to as well. Again, that would not be very complicated at all (assuming the widget is up to date for the version you are running). You can just ask the author about that.
We are not yet running Portal due to a bureaucratic nightmare, so I am not 100% certain about this, but I think this documentation link will make it clear that if you use Experience Builder as part of your portal, you will at times be perhaps 9 months or so behind where the AGOL and Developer Editions are. Longer if you don't upgrade your Portal. It appears the version you are using is from February 2020.
Also note that the current version of ExB has an Edit widget that you should consider using instead of the developer sample one you linked to.
Further, I think you should be able to use the current ExB Developer Edition to connect to web maps, etc. on your 10.81 Enterprise.
Someone please confirm.
