K2 and SharePoint Online

I believe this is possible. but below are some considerations:

1.  Are the K2 Farms of the same version/CU/FP?  I believe it is best if they are.

2.  The 'Manage App Deployment' and 'Manage App Activation' will be at Site Collection level; so will likely need a different site collection for each K2 farm.

3.  Once you have run the 'Registration Wizard' against both K2 farm from the K2 app at the App catalog site, the  'Manage App Deployment' and 'Manage App Activation' will have a new window that will allow you to select which K2 Farm you will be managing, with regards to deployment/activations:

http://help.k2.com/onlinehelp/K2ForSharePoint/UserGuide/4.7/default.htm#Add/AddAppMultiServ.htm