Selling sunglasses in Shopify POS with different VAT when adding a prescription lense

[VinceB1]

We are a UK-based opticians currently implementing Shopify for ecom, and would also like to use Shopify POS in-store. 

Because of UK VAT rules when we sell sunglasses usually they have the standard 20% VAT applied.   However,  if we replace the sunglass lens with a prescription lens, the frame then becomes a medical product which means we then sell the frame (and lens) with a bespoke VAT amount - 8.8888% in our case  (the lens is fixed at the reduced VAT amount).

Is there any way of applying 2 different VAT amounts to the same product in Shopify POS?

Duplicating the frame is not really an option as we have around 400 sunglass SKUs and stock management would be a complete nightmare (unless i'm missing something!).

I've been exploring various Mix n Match bundle app solutions (pick frame for Product A, pick lens for Product B, apply custom VAT to bundle) but have had no joy finding a bundling app that can do this.

If anyone has any options/experience on how i can facilitate this i'd be forever grateful, as I'm currently drawing a blank.

Thanks in advance