Pettit EZ-Poxy Performance Enhancer Additive


I tried it on a recent roll & tip application on a glass boat.  I saw very little difference from previous applications with regard to ease of application or resulting gloss. Too early to tell on the added durability.  It smells pretty damn toxic so there's something in it.  So far I do not see the justification for additional cost.    

Here is a link to SDS  : 

Here is the product usage sheet:

While it has the EZ-Poxy name - it is used for Poly Urethane / Varnish topcoats 

Basically it is a thinner used to lower the viscosity and surface tension on the Poly U
The SDS shows the kind of cyanate compounds that are used in the 2-part polyurethane finishes.  
Is there a chemist in the house who can explain what the cyanates do in cross-linking what’s basically an  alkyd enamel?  

Penetrol is mostly naphtha, a kind of mineral spirits.  Basic paint thinner.