Continuous Improvement stories
CI stories as a result of the retrospective, shall these stories be pointed, time-boxed or what's the best-case scenario here. kindly share your thoughts and advise the best practices here. Thanks in advance.
What is a continuous improvement story? Can it be meaningfully ordered in relation to other stories?
It would be better to pose this question to the team.
Estimating (or not estimating) or time-boxing the work would have an impact on the team's ability to plan their Sprint. Asking the team what approach they would find most helpful to understand the impact of taking on the work associated with these "CI stories" to make sure that they can craft an achievable Sprint Goal and make a plan to not only deliver that goal, but to address improvements to how the team works.
There are no best practices here. The team will probably want to experiment and iterate. Perhaps one good set of experiments would be how the team selects, orders, and plans for the implementation of process improvements. However, the team may need advice and guidance to avoid bikeshedding. The team shouldn't get too caught up in improving continuous improvement that it impairs their ability to deliver value of improve their workflow used to deliver value.
Continuous improvement stories may not be related to the product. The product backlog contains items related to the product. So these items might not be appropriate in a product or even sprint backlog.
If you have work you need to keep track of, there may be better ways - like posting the work on a wikki.
Ultimately, it's your choice. There are no firm rules against what a product backlog item is (PBI), but balance what you do so that you don't overly congest your backlogs.