I replied to an email from Serif about the trial of the PC version of Affinity Photo and I asked about our posts in this forum. Eventually I got this first response to which I sent the link to this forum:
"Thanks for your email and my apologies that you did no receive a response to your initial email.
It is not possible to change the UI in our iPad apps. Could you please provide a link to your forum post as it is very unusual for a post not to get a response."
After that I got this:
"Posts in the suggestions area of our forum do not usually get official responses, ultimately they are a way for our developers to gauge how popular the suggestions are and the more people that comment increase the likelihood of such a feature being implemented in the future. Hopefully adding a light UI is something they have planned for the future as I do know thr desktop apps offer a light UI."
So I am not hopeful that a light mode UI for the iPad version will ever be an option as it doesn't appear that this area of the forum is even monitored.
Just posting this for everyone's information.