Well, it isn't as bad as I feared. You actually can use Extend shields (or RSP) without loosing the full EPtS uptime. Only you need to time it right, at the exact moment it comes of the 15s CD. It then starts a 15s CD on the EPtS, when there is still 15s (ok, rather 14s) left on the first EPtS.
So in fact the only difference is you can't use all three of EPtS, ES, RSP at once (or is it ES and RSP had a shared CD before as well?). But you can still use EPtS with one of those.
My question is: What the hell is the purpose of this change? It just makes Extend and RSP very hard to use (and RSP is only useful if fired at the exact second needed).
Also, weren't you trying to make ES more attractive to (non-expert) players? This goes completely against it.
Therefore, please: Revert the change to EPtS. It just makes no sense, since it even goes against your own stated intents.
EDIT: Just a little fact (that isn't necessarily clear when reading the notes), EPtS is still behaving like any other EPtX, starting 15s CD on any other EPtX on activation (as stated, it has been "added" to another shared CD system, not transferred from EPtX system to ES/RSP shared CD system).
TOIVA, Toi Vaxx, Toia Vix: Bring in the Allegiance class Toi'Va, Ti'vath, Toivia: Add Tier 6 staple KDF ship types: Carrier and Bird of prey. Tae'Va, T'Vaya, To'Var: Give us Asylums for Romulans