Can you please make older versions of the server easily findable/available? I want to try upgrading to 0.1.0 then 0.1.1 then 0.1.2 and finallt 0.1.3 but cant locate these 3 server packs.

I looked, impossible to find. hence "make easier"

Corruption/loss of chunks happens from 0.65 to 0.1, or 0.1.1, or 0.1.3. Chunks seem to be reset to virgin state.

All servers can be downloaded from CurseForge. They have a record of every version released.

Each server pack is attached to each client release on CF, click on each version and scroll down past the changelog.
As for "trashes base" we did recommend new worlds for users once we did our 0.1.0 release

Files tab, https://www.curseforge.com/minecraft/modpacks/all-the-mods-9/files
0.1.0 server pack https://www.curseforge.com/minecraft/modpacks/all-the-mods-9/files/4752160
0.1.1 https://www.curseforge.com/minecraft/modpacks/all-the-mods-9/files/4753674
0.1.2 https://www.curseforge.com/minecraft/modpacks/all-the-mods-9/files/4755774
0.1.3 https://www.curseforge.com/minecraft/modpacks/all-the-mods-9/files/4756123