Cat also makes most of their hydraulic cylinders .... and their specs and quality are among the highest in the industry ( I used to be in Parker`s Mobile Hydraulics Group ) .They are also very tight on their seal standards and cylinder rod finish .... their rod surface finishes used to be less than 8 microns .... which is extremely smooth . One possible side effect of this is that you can get some squeal due to the interaction between the seals and rod under some conditions , ( the rod surface can be wiped so dry that there is virtually no
oil film between the seal and rod ) ,which is probably why they have this additive . Yes , it works and works very well .
You`re going at it the correct way by checking compatibility of the additive with your existing hydraulic fluid ... which is something 99% of the people out there don`t do . I used to see everything from STP to ??? dumped into systems with no regard for what it would do to the fluid , pump seals , wearplates , valve seals , temperature ratings , hose etc .
BTW , you might check with Cat and also see what they say .
Good luck ... hope it works out for you at work .