The upcoming version of Mastodon (2.6) will have improved support for so-called circles (a group of recipients that is less than all your followers)
Mastodon itself does not implement circles, mind you, but e.g. Hubzilla does, and any ActivityPub server could.
Prior to this patch, such messages would appear as DMs with a large number of recipients in Mastodon. After the patch, they will appear just like normal private posts.
再次测试利用 IFTTT 将 Twitter 的 po 同步到 Pawoo