Tips on making materials fewer in numbers? and thank you for taking the time.
For a while I have been working on a character concept and it is reaching the late stages of creation by now. I am happy and positive with the outcome so far, but there is one obstacle for me left.

I have to run this model and export it through a specific addon in Blender, however this addon requires me to use a maximum of 8 materials on the whole work, that is the maximum limit of the addon. Please do not ask me why!

But my work has led me to a stop for now where I am trying to work out the UV map and my materials, I have managed to cut it all down to 10 materials, but this is two materials above the requirement. I cannot remove any more, as it will mess up the UV map? I tried it out, the textures goes crazy.

However, I do use several body parts with the same material.
I already tried to use Ctrl + L to link the materials together, but it did not really resolve the issue for me and now I am at a complete halt.

I guess my question is, does anyone have tips on making the materials fewer in numbers now? Is there a way for me to merge or say make two of them go together to reduce the material count? I can't for the love of me figure this out so far, been trying many features but in vain.

Support appreciated!
Thank you in advance.
Try to bake materials so you can use just one material map instead of all of it. google for 'bake materials in blender' and you will find some tutorials for sure.