We'd like to outline things you can do to get it sorted (and you should do them all):
- Look for alternatives - for many of the older plugins, there are newer plugins that can solve the same or similar problems. Also, sometimes improvements in Indigo itself can offer solutions that weren't available when you first started using the plugin.
- Add a post on this topic listing the plugins that you need updated. Others can then suggest alternatives or perhaps look at the source code for the plugin and see how big a task it would be to update it. Then we'd just need permission from the original developer to open source it (if it's not already available on a source repo site and has a good license).
- Contact the developer of the plugin to see if they are 1) interested in updating it and/or 2) are willing to allow others to do the work. If #2, they can contact us and we can get the ball rolling by putting it into our open source repo where other developers can make changes.
You will note that there is no just wait and see what happens on the list above. That's because that is not a viable option at this point unless you are willing to freeze your Indigo Server, including macOS updates and if you use iOS freeze those as well. In fact, it's extremely likely that all plugins that have yet to be updated will not be updated without some motivation/interaction.
You will need to be active in sorting out your requirements and finding solutions. The community is here to help, but you have to be willing to engage.