I haven't seen this particular currency combination/strategy mentioned so figured I'd post about it.  I've been experimenting with off-meta Atlas strategies just to see what else you can do besides the usual deli-city/juiced GE.  Earlier in the league I had some success with the wisp strategy in farming Rites of Passage so I have a soft spot for those cute little blobs of light.  

Currently messing with Hilda nodes/empowered map boss tablets to try and coax out some more wisp interactions as I feel they haven't been explored enough given the overall opaqueness of mechanic.

Anyway, in my attempts to get reliable super-boss boxes via the spirit of the hare mechanic (fox + hare for true mayhem which I've had happen once this league) I only now realized you can combine the omen of secret compartments and the cryptic key to open a juiced, wisped strongbox at least 3 times.

I'm not sure if you have to have the omen disabled before you use the key or not (I enabled it for the second open only, fearing the omen would get consumed alongside the key and render itself void if used on the first open), but I can confirm the somewhat obvious interaction of giving you 3x opens if used successively.

Wondering if there are some funny interactions alongside the guaranteed wisp-releasing omen as well (hare/fox-chaining, perhaps with two side by side strongboxes, which I've seen proc quite a few times especially with the additional strongboxes Atlas node... who knows!)

All that said, the omen/key combo isn't the cheapest, so it should probably be reserved for juiced strongboxes (spirit possessed well-rolled researchers, +chest level cartographers, exceptional item armourer's, etc.)

Cheers! 

P.S. Please don't (or do, whatever) judge my inventory, I'm messing around with tablet setups 🥶

PSA: Omen of Secret Compartments + Cryptic Key to recycle strongboxes