Some good points and observations in this thread.
@DangerDarren made a great comments about practicing your stops and moving around on the bike so you don't stiffen up.
Some ideas to think about:
Make a list of the things you do when you roll up to the pumps to get petrol. Ask yourself why you do each one, and can you not do that? Minimizing the steps you take at refueling will save time. That gives you more time on the road, or minimizes the time if you need to do something other than get fuel at that stop.
Do you take your wallet out to get fuel? Don't. You need a credit card to get fuel, not the rest of your wallet. Keep a couple of your most used credit cards somewhere in your outside jacket pockets where they are available to you, while wearing gloves. (I use small folding credit card holder that only holds 4 cards. My National Parks Pass and two credit cards live there along with a $20 bill for emergencies)
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Here in the US, tap to pay is becoming more common on fuel pumps. If your current credit cards do not have the tap to pay feature, contact your provider and ask if they offer that, and if so, get new cards with that feature. This shouldn't cost you anything, they will just send you new cards for your existing account. While you're at it, get additional cards if you don't already have them.
The cards I carry in my jacket sleeve pocket are for the same account as the duplicate ones I carry in my wallet. Many, if not most, companies will give you at least one, if not several additional cards for the same account. I have 4 Chevron cards, for example. (Interesting side note, my Chevron card is not a Visa/combo card, just a regular Chevron card. It registers as a Discover card when I put it in the pump. Turns out, it will work to purchase things from any other fuel company or business that accepts Discover too. I can buy fuel with that Chevron card from a Shell, Exxon, BP or no name fuel pump if I choose to.)
On a certificate ride, when I stop for fuel only, I don't get off the bike, don't take my helmet off and don't take my gloves off. My gas cap has the flap removed and a shortened key stays in the cap at all times with a knob glued/screwed to it. The key is too short to work in the ignition and my luggage takes a different style key. This knob came from the hardware store in the appliance repair bins.
So roll up to the pump, shut off bike w/key left in ignition, side stand down, tank bag un-clipped and set forward, gas cap opened, card case removed from sleeve pocket or other jacket pocket, (my mesh jacket does not have a sleeve pocket), then card out and to the pump, either in the slot reader or tap to pay, once done with card, it's returned to card case, case back to pocket and pocket zipped/snapped close, Then remove pump handle, pump fuel, return pump handle to pump, push button for receipt, return tank bag to locking ring, collect receipt, write number of gas stop and mileage on receipt, (just what I like to do, pen lives clipped/velcro'd to tank bag), clip receipt to photo area on dash, camera comes out of outside jacket pocket and take picture of receipt and odo, verify quality, camera returned to pocket, secure receipt in dedicated, waterproof spot, key on, side stand up, start bike, ride away.
If I need to get off the bike for a bio break, my key gets clipped to the outside of my jacket. I poke a split ring through a corner of a pocket flap and either use a valet ring or a carabiner to secure the key when I'm off the bike. This way I never, ever, need to dig in a pocket or remove a glove to get to my bike key.
Find your fuel stop routine, repeat that routine the exact same way, every stop. That avoids errors and develops muscle memory. Avoid extra movements/steps that you can.
If you need to get off the bike to rest/stretch because you are sore, you have issues to sort with your bike. Your bike should be the most comfortable spot to be. Sorting out the small ergonomic issues makes a big difference when you're on the bike for 17-22 hours. That may be as simple as rotating the bars or bar risers, highway pegs, etc. Or may be a choice of accepting discomfort instead of getting a better seat or talking to the local upholstery shop to modify your existing seat to improve things. We each need to decide what's a priority for us.