The other thing that crossed my mind is that if Hapkido was similar to Aikido the extra 1.5 hour lesson in Hapkido (again this is all thats available) would also maybe benefit my Aikido practice if that makes sense?
Could be, could be not. That's true even if it were another aikido dojo.
What's the issue with only being able to train 2x a week? Is that all the classes that your dojo offers?