3c leave second job: Tier 2 extension

Hello,
I have got a second job in the same SOC code with another employer. He wont sponsor my new COS. My questions are
1. can I work with him while my Tier 2 extension application is pending and I am on 3c leave. If so are there any work restriction.
2. does my current COS sponsorer need to update on sponsor management system this fact before or after the CoS is status as used?
3. Is there anything else to take care of that I may not have picked up in my first 2 questions?
-A

1. if the soc code is same, you can work for 20 hours there only.
2. Nothing to do for existing sponsor

Dear iworker,
Thank you. If I understand you correctly
1. I can work while under 3c leave with a second employer upto 20hrs per week and also can continue working with my current employer who has issued me CoS. Correct?
2. Kindly provide me the link to the page number of gov.uk document that states point1 above to show it to my CoS issuer HR as has been demanded.
Cheers

can anyone comment please....