[SEDXC] QSL Advice Please:Putting Multiple Cards in a Single Envelope

[Clark Macaulay]

I have three QSL cards from me to separate stations all managed by the same QSL manager. I read recently that some DX ops specify only one card per envelope but I'm wondering if this relates to keeping the cards FROM ONE CALL SIGN in single envelope.
 
Then again, not having any DX manager experience,  I'm wondering if it is OK for me (from a single call KE4RQ) to include individual cards in the SAME envelope to the QSL manager?  Should I then include SEPARATE return envelopes, one for each station?
 
Just trying to save $1.84, the cost of two additional stamps to the QSL manager.  Maybe it's not worth it but my Scot bloodline doesn't want to spend more postage than needed.
 
Thanks in advance for your help. I couldn't find the answer anywhere in my own resources.
 
73, Clark KE4RQ