By far the easiest way to tame these guys is to use 4 metal Dino gates and trap him inside so he can't get out. Then use a tek Rex to knock him out. Takes 4 element for a 150 and there is no chance of killing it if you hit it mostly in the head?
It's a bit silly that kibble tames it a lot better than rocks or sulfur because even in the dossier it says that it lives off of absorbing nearby rocks and minerals. So mabey they should make it so you have to feed them a rare mineral like obsidian what if they made it so you could tame one fast and with high effectiveness by giving one a few hundred or few thousand obsidian . or what if there kibble was made out of a combination of ores and minerals .