Personally, I'm just keeping a spreadsheet where I manually put my transactions. I have a spreadsheet for each wallet, so I can record transfers between them.

The only flaw I see with your method is that unless you are purchasing noKYC sats, the exchange that sells them to you will soon be required to report that. So the only real way to be the sole provider of information to the IRS would be to exclusively buy noKYC sats.

Beyond that, while I get the appeal of ensuring that all sales are long-term capital gains, as I've switched from FIFO to HIFO, I've realized that a lot of my transactions will be short-term, but that this isn't necessarily a problem.

Let's say I purchase ₿0.001 BTC at $10,000. Then, a year later purchase ₿0.001 at $100,000. Let's compare the taxes if I then sell ₿0.001 at $110,000 (let's just say this transaction takes place less than a year after purchasing the $100k lot).

Let's also assume that I am single and make $65,000/year making my short-term capital gains (STCG) rate on this transaction 22%, and my long-term capital gains (LTCG) rate 15%.

FIFO: Disposing of the early tax lot - long-term capital gains

Cost Basis: $10,000*0.001=$10

Proceeds: $110,000*0.001=$110

Capital Gain: $100

Tax Liability: $100*15%=$15

HIFO: Disposing of the later tax lot - short-term capital gains

Cost Basis: $100,000*0.001=$100

Proceeds: $110,000*0.001=$110

Capital Gain: $10

Tax Liability: $10*22%=$2.20

While I've used simple round numbers here in an attempt to make the comparison clear, your transactions are unlikely to be as clean as these were. That said, I hope it provides some insight on why striving to make every transaction qualify for long-term capital gains, may actually lead to having a higher tax liability than using a HIFO method and disposing of highest cost tax bases first, even if accepting a higher tax rate.