Heads up if you're in the UK, the Nintendo 64 NSO controllers are available for a reduced price. These work on Nintendo Switch Nintendo 64 games but will also work on the Analogue3D.
Also, it let me buy it although my Nintendo Online subscription is from the Americas 🙌 (they're always weird with region locking stuff).
I refused to buy the NSO upgrade while these were out of stock, then when the stock stabilized I grabbed a couple but ended up not getting the expansion pass anyway.
But they've been great for N64 emulation on other platforms.