How tight do I screw in fittings to blocks/radiator/pump?

Probably been asked a thousand times already. Sorry.

I'm using EK G1/4 ACF fittings with soft tubing. On my last build I screwed them finger tight (as tight as I could) then used the 8mm Allen key (provided so I guessed this was OK) and tightened it until it stressed slightly. I could have went tighter but I stopped when it began to not turn.

No issues at all. Then I read that this could break things (it didnt explain if this broke the fitting or the part its screwed into).

I have a new case and will soon be returning to the loop again in the new build.

Im getting a lot of conflicting information online and some responses are 5 years old+ and I dont know who to trust.

My questions are:

• How tight should I tighten the fittings? Is there a recommended method and do I use the Allen key again? Because some say never to use it!
• Is it possible I have broken anything? If so what do I look for?

....Im probably overthinking this...

Thanks guys and girls.