Yes, you can change Store listing on play store whenever you want and there is no limit for this. you can change and improve your listing in terms of Graphics and SEO improvements.
According to Google Developer Distribution Agreement you can change and Modify:
- Application Name
- Icon/ Screenshots
- Graphics/ feature Graphic
- Application Policy and agreements
- Featured Video
- ASO/ Keywords and description
There is no harm implementing these changes but this could take a while to implement changes depending on account health and your geographical location...
This is my application (Play Store Link...). I have released multiple versions and implemented major changes in each version.
I changed icon and graphics more than 5 times and improved ASO couple of times.
This not just improved my user experience but also increased daily installs.
Based on my experience I will recommend continuous changes for best application optimization. and I want to recommend targeting events like:
Christmas and New year, Independence Day, Halloween update, etc...
These types of updates entertain users and increase engagements and also helpful to build trust with your users.