I see your audiogram now.
Your hearing loss is extremely mild so yes, open domes are more appropriate.
NHS audiologists are often not able to do their jobs well.
My Step Mum wears open domes but when she asked for more tubes and domes to be sent out, they kept sending power domes. No matter how much she argued saying, no I wear open domes. They were like, that’s what we have on your system that you wear so we can only send out power domes.