Zero Pricing Issue With Options And Storefronts

So I have had to share products to a second storefront and want pricing hidden for these products only on this storefront. So I have set the price to zero for this storefront.

All seems good until we have had orders for these products at very cheap prices as customers can still select options - and the options can't be removed or price set to zero on just one storefront?

Looks like you should save zero modifiers to all store-fronts at first, then save correct modifier for the store owner only