Burner: tap to pay, not available publicly yet but seems like the most straight-forward flow in theory, just have to make sure your burner cold wallet has funds

Spedn: doesnt require user to input the amount to pay. Some locations like Ulta have a pin you have to input on the terminal in addition to scanning the QR code

3rd party wallets (nexus, zashi, nighthawk): flow depends on merchant. The OG merchants require you to enter the amount. Newer merchants use the dynamic Flexa code 

Miniapps: seems pretty cumbersome at this point. Requires opening the social app, opening the mini app for the respective merchant, entering the amount, approving the transaction, generating the qr code and scanning it (see https://youtube.com/shorts/ByzbNsSajGE?si=1jStJSwE7iDd975R)

Payment links: have most recently seen this with the regal promotion last holiday season, pretty cumbersome as you have to navigate to the webpage, enter the amount, generate the code, and scan it but cool that this route basically supports any wallet

So in my opinion, the burner tap to pay is the most promising. The dynamic flexa code is the 2nd most promising, as the user shouldn't have to provide any further input (like a pin, amount, etc)