If you are using compounds, there is absolutely NO NEED to use leather as a substrate.
Any firm surface will work just as well. We use veg tanned leather for strops because it contains natural silicates that work as our 'compound' for finishing at ultra fine grit size. Covering up these silicates with compound is rather like putting paint on hand rubbed fine furniture; it's certainly not giving you any benefits. By the same token, it doesn't stop the furniture from being used as furniture.
Using compounds rubbed on wooden paint stirring sticks works just as well as using compound on the costliest leather. The strop just doesn't look as nice nor give you the emotional satisfaction of using a lovely leather strop!
If you are making strops, please be sure to keep one good leather strop to be used without any compound. After stropping on your compounded strops, give your blade 20-30 strokes on the bare leather strop to finish your edge.
Stitchawl