AFAIA as per their website :
 
http://beta.focusrite.com/releases/saffire_mix_control/
 
http://uk.focusrite.com/firewire-audio-interfaces/liquid-saffire-56/downloads
 
Extract from a mail I received from Focusrite dated 22/06/2015, after the release date of you referenced download(s) :
 
Hi Jerry,

Thanks for your email.
Currently we are still testing Mix Control 3.6 with other Saffires with the intention of fully releasing 3.6 for other Saffires very soon.
You should be able to use 3.6 with your LS56, however please note that there may be some issues that we're not aware of. If this is the case, you can revert to Mix Control 3.4/3.5, although we'd ask that you do report the issue to us.

I hope the above helps.
Please do let me know if I can be of any more assistance.

Best regards
 
Etc. My case rests m'lud
 
That being said, in for a penny, in for a pound, here we go !
 
Cheers,
Jerry.