any pictures of stiff starter when it peaks/mature ?

Greetings

I'm trying to make a new stiff starter, 50% hydration, feeding it with:

20g starter
20g water
40g flour

It triples in 4-5 hours, but the dome stays up for about 12 hours, with no or little signs of activity. My understanding is that a firm starter peaks when the dome starts to go down, with lots of holes on the sides. That doesn't happen to my starter although I've been feeding it in RT for 15 days now.

Do you think its ready to use yet? or should I keep feeding it more days?

I was hoping if someone please post any pictures of a firm starter at its proper peak, when its ready to be fed, or bake with. I've googled it, but I only find pictures of mature 100% hydration starters.

(I'm attaching a picture of my starter, 16 hours after feeding. As you can see on the left side, the dome went down but there are very few holes in the sides and top of the starter. But when I peel the top of the starter the inside of the starter is full of holes and threads, as you can see in the right side picture).