As you said before, you believe the artist is talented and the lower half of your arm has healed just fine. As long as you take good care of it, stay out of the bath until its healed (in other words dont soak it), dont lay out in the sun as buttwheat says, make sure you’re looking after it, not scratching or picking it should be just fine. Most tattoo artists will include free touch ups once your tattoo is fully healed anywhere it is needed but I’ve never needed one yet and i have some seriously intricate work 🙂