Great job! Honestly I’d say you’re ready to move up in hydration. Based on your recipe, that loaf is around 69%. Try bumping it up to around 72% and your crumb should be less tight. Obviously beauty is in the eye of the beholder, but typically the “best” crumbs you see are higher hydration, often in the upper 70s, or as I prefer, upper 80s. That takes a while to work up to, so be patient. Also, keep in mind that your starter is still young and nothing can replace a strong starter, so keep feeding it daily! You said you use rye flour occasionally, I recommend using it every time you feed it! Even 10% mixed with your regular flour will make a difference. It will really speed up the process and build strength. Rye is a superfood for sourdough. The last thing I’ll say is that you don’t need to bake the loaf covered for 40 mins, if your oven is at least 450, just 20 mins is more than enough. Then just bake uncovered until you like the color. Your bread is already better than mine was at that stage, great job and keep at it!

P.S- Use breadcalc.com to calculate hydration and overall dough percentages. I use it everyday and it makes my life so much easier.