Hi and welcome 
Just to add to what Gaz66 has said, I think the general advice would be to get the EXUP working so you can enjoy the bike as Yamaha intended, with it working and a 4 degree advancer the low down grunt and smooth power delivery is amazing and great for sensible riding especially with the misses on the back. However as already said if you take the valve out and ride it you will still be able to enjoy the bike and you won't miss not having the EXUP as you wont know any different, just don't ride a bike with a working one :lol
Just to add to what Gaz66 has said, I think the general advice would be to get the EXUP working so you can enjoy the bike as Yamaha intended, with it working and a 4 degree advancer the low down grunt and smooth power delivery is amazing and great for sensible riding especially with the misses on the back. However as already said if you take the valve out and ride it you will still be able to enjoy the bike and you won't miss not having the EXUP as you wont know any different, just don't ride a bike with a working one :lol