Lunar Client used to have this feature, so that even if u had ur client open for extended periods of time, you wouldn't need to re-login again and again (im pretty sure it did). Currently you are forced to re-login to minecraft if you leave the server ur on and try join another when your client has been open for a long time. If you fully close lunar client, and re-open it, it gets the new auth token and doesnt require you to painfully log in. Other clients do not require you to fully close the client and re-open, and instead have rolling new auth tokens being fetched.
#Add updating login token auth instead of only happening on program startup. (Lunar used to do this)
warm sluice
neon lintel