You can manually create a new StyleAttributor
with parchment
directly:
import { Scope, StyleAttributor } from 'parchment'
const SizeStyle = new StyleAttributor('size', 'font-size', { scope: Scope.INLINE })
Quill.register(SizeStyle, true)
I got the idea from here: https://github.com/slab/quill/issues/4262#issuecomment-2231359742