Yes the betas disappeared.

The only interesting one is the pre_whn2013_demo. It was a build of the game that was avaible to playback older demos that had been broken in newer updates.

There are at least 2 possibilities why valve removed this beta

1. Valve fixed demos. Not sure about this one as I do not have old demos to test this.

2. Valve did it to make item schema exploits more difficult.

In the current version of the game tf2 wont start unless it has a valid items_game.txt. The file is signed to confirm that it is correct.

In previous version you could simply edit the local copy of items_game.txt and try out all kinds of exploits. Stuff like using giftapults as keys.

If you were to use the old version of tf2 it is still possible to use a custom items_game.txt and try to find exploits. It is not possible to play online with them as you will have a version mismatch if you try to connect to a server.

It not impossible to use a custom items_game.tx. However looking for exploits using a custom items_game.txt nowadays it has gotten significantly more difficult so a lot less people are trying and a lot less exploits will be found in the future because of this.

Care to share your version, it sound interesting

I already tried that, the damage taken event is not functional in tf2 for some reason

I am aware of it but do not know how to fix it.

Author here.

I have stopped taking request for editing huds to include this bar. To hud makers who want to include this bar with different size/position color; I made a little script to generate all elements of the bar and the animation here: https://github.com/martijnterpstra/medHUD/blob/master/bar_generator.py

I already have a few other things I am working on but if you have any suggestions, please let me know.