Hello,
As of now App studio and Dev portal both creates manifest with v1.9. The best option you have is to create the initial manifest with these and then download to do the further manipulations.
Let us know what v1.10 feature you are using
Thanks,
Hunaid Hanfee
If the response is helpful, please click "Accept Answer" and upvote it. You can share your feedback via Microsoft Teams Developer Feedback link. Click here to escalate.