Another streaming replication question

Thank you all for your responses to my questions about streaming/cascading replication.  I have them ironed out and running on three postgres 9.4 sandbox servers. 

My question is not 'how to ' but more 'best practices'.  We currently have hot standby non-streaming replication with one master serving two standbys in parallel. We wish to convert

to streaming replication.  My concern is that the logshipping load can be quite high - up to 40 16MB logs per minute (during off-hours maintenance). In our current hot standby

environment the logs can queue up on the master side during this period - eventually, during times of lower load they do catch up.  So, a couple questions:

   1.  Can streaming replication work in this high-load situation?

   2.  What, if anything, can I do to make it work better?  Perhaps convert to cascade? Master -->standby1 ---> standby2

I have attached the postgres.conf file for our master for reference.

Any insights welcome.   Thank you.

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