How would you even do this? In a casino, coming and leaving are easier to define. Much less so in Gpokr. Do you punish someone for e.g. going leaving the table while they go to the bathroom? while they cook dinner?

No. It's easy af. You literally just make player rebuy with the same amount they stood up with at a table for 1hr, 24hr, or some limit.

Example: pocketaces24 stands up with $212k at $500/$1000 stakes. If pocketaces24 sits down at same table within x seconds, they sit with $212k, not $100k default.

And it's not a punishment. It's just a fair rule that affects everyone, and protects against the unfair and unsporting behavior of ratholing.