Hi @Robin_K , @Jonathan_Maher ,
Dan here from Vevol Media 
(Shopify Experts), I am not 100% sure this would help you but I’ll explain what we did for one of our clients based in the UK.
They had similar issues and they used the Exentify app (which, without upsetting anyone, slowed down their website) so we removed the app and we’ve added a dropdown on their Home Page that allows the client to switch between seeing the prices with VAT and without VAT. See attached file.
Feel free to get in touch with us if you think this could help you too.
