Yes, if you try to buy an asset with BTC, it takes about an hour to complete
I'm still not quite get why it should take one hour to complete. Let's say a block takes 10 mins. Matching takes 1 block, Btcpay 1 block, so 20 mins, what do I miss.
The reason is blockchain reorganizations, which basically rewrite the recent history of transactions, and Bitcoin payments are irreversible. So a blockchain reorganization can invalidate a BTCpay, because it can remove a previously valid order match from the ledger.
It takes 3 days to go through coinbase, and you're complaining about an hour?

The faster you trade, the faster the high-frequency trading algos will take your money. If it takes an hour to trade
soybeans that take me a year to grow, that seems like a good deal to me.
What I do need, however is a way to set up a BTCpay escrow account, a way to have make the BTCpay happen without my browser being open, and some sort of two-factor auth for counterwallet.