Hi, from my experience with WES, they are more concerned with the time spent studying at that level rather than the awards anyone has. I.e a top-up degree may only be seen as 1 year at Uni. So hopefully for you, they recognise the HND as 2 or more years at Uni.
They gave me a Post Grad (semester) for a UK part time PG Cert that took me 12 months. I can’t use it at all as I only have 1 year at University.