Should I fill gaps with mortar?

[Omaha]

If the gaps do not extend to outside, then they don't need filling, but you may consider filling them for a nicer appearance.

Great, thank you. That was my understanding but wanted to be sure. None of the gaps extend all the way to the outside so I’ll plan to keep moving forward. I’ll scrape off the excess mortar before moving on the outer arch.

[MarkJerling]

If the gaps do not extend to outside, then they don't need filling, but you may consider filling them for a nicer appearance.

[Omaha]

Apologies as I’m sure this has been asked before but I couldn’t find a straight answer with search.

I just finished my dome yesterday (will create a photo post soon) and am ready to start the outer arch/chimney. My joints aren’t exactly as tight as many seen here though. Everything is holding well, but there are many gaps when looking from the inside (especially near the top). Should I fill these with mortar?