My questions are regarding workflow limits in a SharePoint Online environment. However, the article for SharePoint Online limits does not offer any information regarding workflows. I referred to the workflows limits of SharePoint 2013 here
Workflow postpone threshold of 15
Is this the same for SharePoint Online? If yes, can it be increased? Say there are 20 workflows running simultaneously: 15 would be processing, and the other 5 would be queued? Does performance decrease when the amount of concurrently processing workflows increases, particularly when the limit has been reached?
Maximum list size for workflow lookups to non-indexed fields - 5000 items per list view
It is defined as:
This limit is a result of the maximum view size limit. When this limit is exceeded, workflow lookups to non-indexed fields will fail for non-administrative users.
Why 'List view' and not List? What does this mean exactly? For e.g. the 'Set field in current item' action will stop working with non-indexed fields? And what else? If not, what stops working? I administer a SharePoint site, in which a library has exceeded the 5000 document mark, but not the 5000 root folders. Could it be that the workflows have not experienced this because the root folders have not exceeded 5000? (For e.g. Lookup fields looking into this list stopped working when the 5000 document limit got exceeded)
HTTP Web Service requests
Nowhere does that article, or anything else I could find online, discuss HTTP Web Service requests. Say several workflows are started concurrently and they all require a web service request to be made, do the workflows' performance suffer any degradation? And what is the timeout for the 'Call an HTTP Web Service' action in SharePoint Designer workflows? Perhaps anyone can speak from experience unless there are hard stated facts.
I am trying to plan forward here, and any insight would be greatly appreciated.