Hi Raja,
First, I want to say thank you for the images you have posted. They are good because features like the striae and inclusions are visible. 
I am not sure I can see any curved striae, as Tonya (@taurean) has hinted at, yet it is very possible the curved features are very subtle.
You mentioned the orientation of the stone seems to display or hide a “curved” effect. That can be induced from the quality of the optics being used, or as some literature here in the IGS library has stated, internal stresses in the crystal can produce optical distortions. Honestly, I am not seeing truly curved striae.
I had mentioned earlier that there was silk or bubble-like strand inclusions in your stone. These are very visible in the lower right portion of image: 20250326_134511 from your Ruby natural or synthetic post. These linear strands seem to be broken up, which can be an indication of heat treatment. I recommend observing these under high magnification. It would be awesome to see those images. 
A good resource to do comparison of inclusions can be found at the Hyperion Inclusion Database at Lotus Gemology. Click this link to see Inclusions in Natural Ruby with Heat Treatment, as an example.
You can do refined filtering for specific types of inclusions in both natural and lab grown material (if images exist in the repository).
Secondly, not that this has any relevance to your initial questions, I am not sure the images in this post are at 200x magnification. The field of view (FOV) seems too large and too bright, especially if you are using dark-field illumination. The amount of light needed for higher magnification becomes exponentially larger the higher you go. Admittedly, most phone cameras have good auto-balancing algorithms that can help post-process with lighting and weak contrast and hue artifacts. This could account for the nice illuminated field of view.
Depending on the phone and camera lens, they typically have up to 4x optical zoom with any additional zoom capability being digital. Digital zoom does not count towards the physical optical magnification value. You probably have 80-90x magnification, which is very good from a gemology perspective.
-Cheers!