TUI Hand Baggage

I went with tui 2 months ago and saw loads of people with small suitcases as you describe as hand luggage

It always astonishes me how big the ‘small’ suitcases are! However, you may be allowed 10kgs of hand luggage per person on certain flights rather than 5kgs, so check on your travel documents. There tends to be a mix of cases, rucksacks, holdalls so all different shapes and most fit in the overhead lockers. Do be aware that quite a few of what should be for certain seat numbers are full of medical emergency equipment so your luggage may have to go further away from your seat, where there is room. You are also allowed a bag of ‘shopping’ which can go under the seat in front i.e food/drinks/magazines/gifts,

Our documents say that the size needs to be strictly adhered to but as we have hold luggage included in the price there's no need for a wheely case

It'll depend how anal the staff are feeling. If the plane is full and they have to pick people to put hand luggage in the hold, which seems to happen often now compared to last year, they often pick people with bigger looking suitcases or get the spacer out to see whose luggage doesn't fit.

Unless that happens, though, or you get a very rule conscious check in agent, you'll probably be okay.

Has anyone experience with TUI boarding passes, just using them for a one way flight short notice buts its not clear if i would be able to use the phone/app for boarding pass or need to print

We always print boarding passes (at home) although have seen people use the one on their phone, basically the image gets scanned at the departure gate.