UDim limit and numbering correct? [FIXED]

Hi, I just checked what the max size of UDIM tiles you can have in unfold 3d. If i'm honest 20 might not be enough for hero assets, crazy I know.. but I regularly work on some films with hero assets getting over 400 UDIM at 4k. That is some of the largest assets I ever worked with and you could work around it but you would prob be wanting to load it straight into maya or whatever 3d package and back again with as few steps as possible.

I wanted to check with you Remi, but i think the UDIM numbering is incorrect in UF3D.. traditionally UDIM tiles only go 10 across U value and then upwards from there in V to whatever number (infinite?). This is how feature films assets are setup.
Here is how it is in UF3D and a modo uv screen grab imgur.com/a/AW1vo - I think you actually get doubling up of udim number in UF3D the way it is now? see tiles 1010. This is also important as we sometimes run the udim tiles through automated scripts as though they are a sequence of rendered frames - so sequential numbering is important. Does that make sense? am I setting it up correctly?

also, should it start at 1001 and not 1000 udim?

Thanks,
Richard