I am writing rules for EW Hollywood Platinum currently and it isn't all that hard. It just takes a tremendous amount of time. What is nice about the hollywood series is that you can write one set of rules for all strings using the TemplatePro folder and a few other random articulations (you'll need the KS instruments as well to round out with trem and trills).
Some things to look out for: 1) read the manual very carefully to understand which controller is used for volume and make sure your articulations match. E.g., the NV NV ... MV NI patches use modulation (CC1) whereas all the SUS instruments use CC11. If they don't match, you will have crescendos adding vibrato and dynamics manipulating cross-fades. 2) Use the short-MOD articulations as they pack 4 different types of short notes in one patch manipulated by CC1. 3) Legato articulation rules are difficult as the nuances with slur+port get ugly quickly. That, coupled with how velocity influences the latency between source and destination note make programming them in Notion next to impossible. I'm sticking with the simple Legato Slur RR LT for under-slur rules.
In a nutshell, your rules will be a combination of "Send CC", "Change Channel", "Change Channel + Send Keyswitch".
I've been working on these rules now for over a week and am just about done with strings.