This is a bit of a feature request, per_page is not part of our API (not used by the client at all). This would not fully solve the issue cause per_page would need to come with an upper limit of say maximum of 100-200.
Is there a specific reason you are looking to override page sizes?
Yes, We have a customer page to get the topics with waterfall flow.
Sure I think this is a feature request.
We can use default per_page and remove the per_page query.