This is probably less work than either of those events and you can be done quicker as well. Explorations aren't necessary, just farm Power on Power (the last story mission we're up to so far) for something like 2-6k eggs per run and decent rank exp. Stealing eggs is 100% chance, but it isn't even strictly necessary unless you're relying on explorations. Best case scenario in Power on Power, you're looking at 150ish x 5. That's nice but not dealbreaking.
The Second Knife (dagger that gives Dual Wield) and Cold Snap (+15% ATK/MAG when equipped with heavy armor) are the one-off prizes and arguably the most attractive ones. Depending on how many copies of Dual Wield you're sitting on, Second Knife may be less important, and Cold Snap's value is also variable based on the units and TMs you have.
With all due respect to Lyrian, until I see some solid data, I'm holding off on ascribing any new or even existent effect of Xon's passive (and/or Locke's) on the eggs. I was around for Mogcakes when everyone was talking about how much better rates were with one Locke, nevermind if you could get your friend unit as Locke too... then it turned out it didn't even work on the cake mats.
Confirmation bias mixed with the placebo effect mixed with good ol' gamer superstition means I'll be taking a wait and see approach with this one. Consequently I'm going to suggest people not go crazy for Xon until there's something resembling testing on his passive.
