I am wondering how did you manage to get so many jobs with unresponsive clients in such a short period.
Keep on mind that not the fact you close the job may affect the JS score but the activity on that job in correlation with the rest of activity on site.
Fixed price jobs are closed by upwork after 90 days of inactivity. Some say its better to let upwork close the jobs but the reasons given so far, in my opinion, are to keep an "inflated" JS score and avoid taking responsability for the activity, which in a way or another its just a matter of time.
Questions you have to answer to yourself before considering to close:
- did you complete, no pending revisions?
- did you get payed?
- did you meet the client expectations?
- when is it the best time to close a job? You must communicate to the client your intentions to close, show interest to continue work when available, give some time.... The fact you keep a job open with no activity/payments affects the JS ... you need to find a balance
- do you close them all at once or one at a time?
- do you close it when you have no recent jobs completed with feedback?
Unless i got it wrong. Why do you say cancel? I supposed you done some work and just want to close/end it because no additional work is given.
Canceling a job means you entered the contract and did not do any work or pending revision from client, or you didnt get payed... and this could lead to a dispute ect. In such case its a more complex situation. Although I wouldnt get the CS involved you should get in touch with them at least to give you some indication about possibilities in such cases.