I'm restoring multiple (tens) email accounts from MBOX files using the "ImportExportToolsNG" add-on, however when I start the copy from my computer into the email account, it copies only one message at a time, sequentially, which is a problem because the MBOX files contain large numbers of emails (thousands each). It would be great if I can enable an option somewhere such that Thunderbird uploads several messages simultaneously to speed up the import. I'm not expecting guarantees such as "it must upload 10 emails every X/seconds" or similar, just adding some parallelism to the imports would be enough and greatly appreciated! Thanks in advance!