I used to think that earning testnet points was like free airdrops, since it cost no money and I wouldn't lose anything. Now I understand: once you start "expecting" those points to cover your costs, you're already paying — with your time, opportunity cost, and emotions.

How to set a stop-loss? Honestly, don't be stubborn with yourself. Set a limit for each account / each chain: no more than X hours of effort, no more than X gas spent (don't pretend, cross-chain / mainnet interactions will cost eventually). When you reach that limit, stop, even if the group starts shouting "last week to push hard." Also, the kind of migration speculation before maintenance/upgrades or hard forks is the easiest way to get caught up: you're not practicing, you're chasing hot topics.

My simple stop-loss signals are: staying up late, borrowing money, or feeling "if I don't do it now, I'll miss out" — immediately close the webpage and go to sleep. Life is more important; points are not urgent.