Of course Korean language is no problems developing any application using VFP with English version. I think you may misunderstood the meaning of the word 'localization'.

As you know MS has their own authorized distributors in Korea.
My company can not be a authorized distributor without permision from MS.
But we can purchase MS products from any where even USA.
Do you think this purchasing process will be a illegal behavior?

Maybe the customers who purchase VFP regards to support any technical issue from the company which purchased the products.
But So long time ago, MS local market strategy and technical support for VFP does not satisfied those who use VFP.

There is no benefit to puchase from MS authorised distributor with high price.