Please be aware that MUSCATE reader is updated for VFS compatibility on SNAP-VFS branch, so consider starting changes for new product version 2.1 from the new reader version within SNAP-VFS branch. (otherwise it will be complicated to merge the changes)
Major
See https://forum.step.esa.int/t/snap-plugin-to-import-s2-l2a-products-from-theia/9950/16