Figured this is best place to ask this, I am putting together a cure set for drk (cause I'm lolcrazy :p ) and I have a 102 spell interrupt set as well but I play on vanilla, is there a way using macros and equipsets that I can utilize these like start in fc/switch to sid set/end in cure pot set?
Short answer. No.
Long answer. There's a few different issues with this.
For starters, the fastest you can normally consecutively change the gear in a given slot is about every 0.5 seconds. I don't really know how much FC+ DRK can get, but with capped casting time. the typical cure cast time goes from 2.5 sec, to 0.5 seconds. Since the precast is equipped before the spell is actually casts, and there's a slight time delay( very slight) between every line in a vanilla macro, you could at most precast and midcast. There's not enough time to get the last swap in.
But even if there was.... you'd have to know when to trigger it. And this would be different for every spell(that differs in cast time) But the bigger problem there, is that vanilla macros only support whole number waits. you can't use decimals. So you can't have it wait 0.5 seconds or 1.5 seconds. only 0, 1 or 2, etc.
So if your spell would finish 0.7 seconds after starting, you could only trigger the swap at 0 or 1 seconds. This would tend to make you either cast in the SIRD gear, or have gaps where you can be interrupted.
Next problem... due to lag between you and the server, trying to swap extremely close to when the spell resolves is mostly likely going to have unreliable results. you might get full potency sometimes, and not others. might even get mixed results, where the spell resolved halfway through swapping a gear set.
Basically, either midcast in cure+, midcast in SIRD, or make a hybrid set with capped SIRD and whatever cure you can fit in after.
And for reference, when to trigger the potency swap so it equips just before the spell resolves is something gearswap doesn't handle well either. It would have to be calculated, and wouldn't have the reliability of the other packet based triggers.