hm.. setting up the model UV to use the first fourth of the quad-texture.. i'll have to try that with something.. i sure have written it off as just 'not working' in this previewer xD
@Veratai I see. Scaling and tiling is a VRM 0 feature and I've used it before in my models and it works perfectly fine, works in the preview with no problems as well. So you probably did something wrong. In VRM1 that feature was changed and removed from main shader properties, but it still remained as a serialized material property for maintex. So I wouldn't be surprised if formatting for VRM 1 broke the model as well. In any case, you shouldn't do it like that specifically because it might break in this way. Instead you should adjust the UV map on the model itself (which can't be done within unity). It's a lot more effort but it works without issues.
you can replicate it with this tutorial https://www.youtube.com/watch?v=MIzJtdvgdb0&ab_channel=Suvidriel about 2:45 minutes in. as far as i know, a model using that kind of texture, and the texture coordinates like it, will appear 'broken' in the previewer, and not elsewhere