I would really love an "undo" button

I think this Feature Request, a revertible buffer for the UI, should be incrementally implemented as part of on-going maintenance. Each UI item should be user slide-able, to allow the player to change his mind, up until tick transition or turn jump.

Maybe this should include tech trades as well, since there would need to be a way to revert accidental mouse click for those also ? The recipient could receive an email that a tech trade is pending / reverted, but not receive the actual tech trade until committed at tick transition or turn jump ?

Revertible buffered UI should work fine when the player is controlling their own empire.

Currently, it is theoretically possible to trade tech across the entire galaxy within less than 1 tick.

But with Revertible buffered UI, player to player interactions would be delayed staggered tick-by-tick across the galaxy.
The benefit is that transactions could be taken back by correction, but the cost is that transactions are delayed until the tick transition.

So maybe for player-to-player interactions, there could be a commit or confirm button, that allows verification confirmation. This would satisfy the need to be able to make corrections, allowing an “UNDO” for tech trades or cash trades.

There is a confirmation button for tech trades now, if I recall. I think this was a good solution as the player-to-player interactions should remain zippy as player-to-player stuff can often happen MUCH more quickly than how long it takes for a tick to happen.

I’d like this too, buying science on a bad star accidentally early game can be crippling and I’ve done it a few times.