JourneyMap is unable to intercept the respawn from HardcoreRevival it seems. As it doesn't create the death point when I press give up.

JM on the client can really only try to capture a deathpoint by detecting player.isDead on a client tick and then grabbing the player's final location. Assuming you have the Create Deathpoints option enabled, my guess is something in HardcoreRevival is pre-empting that check? Relevant code in JM is here:
https://gist.github.com/techbrew-mc/b4149b2d3f4a9398f5dffdae8c1a251f