Cheers @Maggie8K this is handy.
I would also add for anyone travelling into the UK from a less technological advance county (looking at you Albania) to have a digital or paper copy of your ETA with you. It may have changed but in June last year at airport check-in our passports could not be scanned and we no longer had the confirmation email. We had to apply again in the airport. Incredibly stressful and a reminder that while more is becoming digital not everywhere is equipped for it.
That’s a great callout. Plus, tech simply fails at times, unfortunately.
Yeah, like all those automated scanning gates, that either are down or people don’t know how to use them, leading to long lines 
Yes, that happened to me and a bunch of other folks in Italy within the past few months – we ended up having to wait on one set of gates while others hung up and had to be rebooted.
And in Hong Kong in October, we stood in a huge line, because only a few check-in kiosks were functioning. There was no indication that many weren’t working, so folks kept going through the online process, only to get hung up toward the end. I don’t know why they didn’t just take those kiosks offline.
@Maggie8K, thanks for sharing.
On related note for those with multiple citizenships then some countries - e.g. UK and think also Canada - have recently announced requirements on passport usage. For example - UK citizens arriving internationally to UK border security must use their UK passport (or certificate proof of citizenship). Suspect many people already did this - and it would be required to avoid visa fees per chart - but soon a legal requirement.
Unfortunately there is a glaring error in the chart, ETIAS is not for the EU but for Schengen countries. That includes the 26 countries of the EU plus Switzerland, Norway, Iceland and Liechtenstein.
ETIAS is not scheduled to launch until late in 2026.