I understand what you are saying, however, is it possible for you to share which changesets in the nopcommerce core that were added for 3.60 which your plugin requires? I ask because I have version 3.40 and will not be upgrading, and would gladly(and possibly already have) add those changesets which make it possible to use the RichBlog plugin.
Here is the changeset that we asked Andrei to do specifically for the RichBlog plugin and this is the reason why we didn't release the plugin for nopCommerce 3.5. We waited for this changeset in order to be able to release the plugin.http://nopcommerce.codeplex.com/SourceControl/changeset/f240106ff019d347b7bc7ce5dc92f5274159ee33
I don't see how knowing which changeset is needed could help you run the plugin for nopCommerce 3.4. Please note that there might be other changes since nopCommerce 3.4 to nopCommerce 3.6 that could possibly cause problems.
As you know nopCommerce is not backward compatible with previous versions there are a lot of breaking changes between the different releases. That is why you can't have a plugin (no matter which one) for one version to work for the previous or next version.