Any chance of long sleeve model as well?

Yep, working on it 🙂

Here we go : https://alexmichelet.github.io/3dkits-viewer/
Long/short sleeves, and tucked/untucked shirt

Thank you so much, mate.
It is a mystery to me why SI has not done this yet...

An amazingly useful thing! I propose to include also the ability to view the number on the back, to understand how the commercial is seen from the back

Wow mate this is really insane! Will definitely help making kits more consistent and improve the overall quality. With this and the 2D kit converter we really got all tools to rapidly produce graphics for FM21!

wait, is there a 2d kit converter?

An amazingly useful thing! I propose to include also the ability to view the number on the back, to understand how the commercial is seen from the back

The game 3d models don't have the information on the position of the number, I've searched the game files to find something else in that regard but I did not find anything
I'll keep searching for now, but it's not likely to be a thing at this point

I may manually add a number to the models but it will probably be tricky to show the actual way it shows in the game without using proper game files

You can use this layout and add it in your kits. This file was available before but I have tweaked it using this marvelous new tool.
Orange boxes represent areas where you shouldn't place logos; over player's name and numbers on back and shorts. The model itself is bad in that regard, and name and number are oversized. You can forget placing anything above player name, because it's almost touching the neck

That's brilliant, thank you. Sorry to bother you but could you do that again, but with white mesh on completely black background? If it's a lot of work, nevermind