Yes. without any problem. If you use Mastodon vanilla you may find that you have to scroll long and hard because it doesn’t collapse the post with a “Show more”, but not much more

Many Mastodon clients and Mastodon forks already handle this issue adequately, as do other software in the fediverse such as Pleroma/Akkoma and the Misskey forks.

It doesn’t really affect, the protocol does not define any character limit