More experimenting with a Lanxivi X1 Retractable Fountain Pen. I used black masking tape to fatten the barrel grip area.

I tend to have a heavy hand when drawing which can spread nibs. The ib feels very solid and the flow has been smooth and steady since the get go. Capped it's pretty short, about 4-1/3 inches, so it's compact. With the cap screwed on the back and the nib extended it's about 5-1/2 inches.

Picked it up on Amazon for about $45 USD.
https://www.amazon.com/dp/B096VLLJPN