That is a pretty open grained wood, so you will never sand out those little voids. I usually don't worry about seeing them even after fully finished because it is a characteristic of the wood and I like the natural look over a thick glossy look most of the time. That said, when I want to achieve a thick glassy finish with none of those flaws, I do add a step before CA finish (many here do some variant of this). Once I sand through 400 grit (including with the grain), and leaving the sanding dust on the call from that grit, I'll get a fresh piece of 400 grit and drizzle thin CA on the call while sanding, coovering the entire call. This creates a bit if a CA slurry that begins to fill the voids. I let that dry naturally (no accelerator), then sand dry with 600 spinning then with the grain. Then, with a fresh piece of 600 I do another CA drizzle while sanding. Once dry (again, no accelerent), I'll sand with a fresh piece of 600, both spinning and with the grain. The end goal is little to no surface CA but all voids filled. If I need to repeat a step to achieve that, I will. Once achieved, I apply the CA finish as I normally would (multiple coats then wetsand with micromesh through 12000 then buff and polish).
