Once you upgrade from Mac OS X 10.6.8, you will no longer be able to print from Photoshop. You must use Print Tool.
First of all, we never recommend that you install upgrades without first installing to a partition (so you can revert). Since Mac OS X 10.5, Apple has been experimenting with “silent” color management taking place behind applications and converting images prior to allowing them to be printed (even if the application itself is using its own color management system).
Upgrade to a partition and then test your color printing ICC workflows and any critical applications that make use of color management in some way. If all is well - then install your upgrade to your main partition. That way you first stage the upgrade in case it breaks something.
We have not tested 10.9.5 yet ourselves. We will have a 10.9.5 machine here in about a week. But, according to QuadTone RIP versions 2.7.5 and Print Tool version 1.1.0 are both necessary to use Mavericks (10.9)
We prefer printing from Photoshop - so all of the print servers at Cone Editions Press operate on Mac OS X 10.4.7 which is the last operating system from Apple in which they allowed users to color manage exactly the way they want to. We have the most control with this OS. You can always buy an old used Mac with OS X 10.4.7 or 10.6.8 on eBay for $150 or much less - and use it as a print server. Then do what ever you want to with your main imaging station without hurting anything Piezography. Apple can break things quickly…