Fresh zest....to "dry zest" or late addition boil?

Quite some time ago I did a wheat with cascade and "dry zested" with 2 lemon peels worth of zest (just the very outer zest, no white). It turned out good, the lemon was a good match with cascade. I added the zest to the secondary, but have not used a secondary (or zest) since.

My wife really likes Widmer's Shaddock IPA, It is their X-114 Citra IPA with grapefruit peel added.

I'm going to brew up a an extract hop burst IPA with Amarillo and Simcoe (cause I don't have Citra).

Anyone brewed with grapefruit zest? What would you recommend? I'm just looking for a little aroma and flavor.

I'd add the zest at flameout or just before. Last I zested I added it all at 3 minutes. Recipe said 5 but I wanted flameout. My brain compromised and went 3 instead. Still fermenting so I can't say how it turned out.

I use it regularly and add it at flameout. You can also soak it in vodka and add it before bottling or secondary

I used it for a honey wit. I added it at 5 min. But you could also do it at flame out. The key is to add more than you think you need, especially with an IPA, because it will be over powered by the hops.