-Sometimes when telelporting, player can tp into a wall suffocating
-Everytime rtp is used, the server lags for ~5 seconds
-When teleporting (not using a portal) between dimensions, the player's exp bar is shown as 0 until relog or using a portal. This also affects enchanting/using an anvil until you fix it.

I am using version 0.30.0-mc1.19.2

Sometimes when telelporting, player can tp into a wall suffocating

Hmm, I have logic that should prevent this, but I might be missing a case. Does there seem to be anything unique about the terrain when this happens? How often does it occur?

Everytime rtp is used, the server lags for ~5 seconds

That's longer than I'd like, but this time period is going to heavily depend on drive performance. The destination chunks have to be loaded from disk in order to check for a suitable landing location (and they'll need to be loaded anyway to eventually send to the client). If the target chunks haven't yet been loaded on the server, they will have to be generated in real time, which is CPU intensive. Not much I can do here, this is standard MC chunkgen.

When teleporting (not using a portal) between dimensions, the player's exp bar is shown as 0 until relog or using a portal. This also affects enchanting/using an anvil until you fix it.

This is an ancient MC bug, see this comment for a fix: #128 (comment)

Sometimes when telelporting, player can tp into a wall suffocating

closing due to inactivity / lack of repro for the bug case. Will reopen if there is a repro provided