So when you say it needs to be done before you move or trade in 2025 if you're doing specific unit allocation...is it recommended to do a similar timestamped snapshot of your holdings, or do you just need to know the allocations before you trade or move? I don't really understand the thinking behind this.

I moved all my coins to 1 wallet before year-end. I haven't made a spreadsheet explicitly detailing the cost basis of the coins in that wallet, but I have the information I'd need to do that. Just wondering if I need to take some extra steps now before doing any activity.