This release includes a frequently requested feature for this plugin: to minimize the number of source files that are sent to Etherscan for verification.
Now hardhat-etherscan will do its best to only send the file of the contract and its dependencies. It is possible (but unlikely) that this produces a different bytecode than when the whole project is compiled; if that happens, the plugin will detect it and all the files in the project will be used.
Thanks to @kartojal for doing the first steps towards this!