Monarch Mk2 is close to an upgraded Dusk, with very similar tonality.

https://crinacle.com/graphs/iems/graphtool/?share=IEF_Neutral_Target,Dusk_S2,Monarch_Mk2

I have it and the OG MEST and I prefer the Monarch Mk2. MEST has more "holographic" soundstage though, that's the party trick it does. MEST Mk2 is meant to be better tuning than OF MEST but slightly worse in the technicalities.

Monarch Mk2 still has very decent soundstage for an IEM, just not quite on the level of the MEST, but also arguably sounding more natural. The other technicalities are, possibly even better.

ThieAudio Oracle is even closer tuning to the Dusk, but I think less on the technicalities than the Monarch Mk2. I think. I have both, I haven't A/Bed them. I enjoy the Oracle very much though, the main tonal difference is the Oracle has just that smidge more mid-bass than the Monarch Mk2.

https://crinacle.com/graphs/iems/graphtool/?share=IEF_Neutral_Target,Dusk_S2,Oracle

Oracle has better treble than the Dusk, I think it is an upgrade. But if you want to spend ~$1,000 and want a better Dusk, I think just go straight to the Monarch Mk2, it's the obvious choice.

The Diva looks interesting, I haven't heard it. What I'd be most concerned about with it is the bass, in the min bass, it looks like too little. In the max, too much, although I could see that being a "fun" tuning and I think I would like it with the max bass, but not all the time. The max bass puts the rise in the same place as the Dusk, but it goes up a LOT more, like it's +15dB which is nuts. I have the Variations, and it's nowhere near as much bass as that, and it's sometimes too much, I think as a general tuning the Dusk, Oracle, Monarch Mk2 are better tunings.

While the issue with the half bass, it looks like it is pushed too far down, and just starts the rise too low. I have a few IEMs like this, it almost identically matches the curve on the Symphonium Helios, which is a great IEM with the best treble I have ever heard, but simply sounds too lean due to the bass being pushed so far down.

https://crinacle.com/graphs/iems/graphtool/?share=IEF_Neutral_Target,Diva_Half_Bass,Helios_Sym

The Dioko also suffers from this problem. It's just too far down. Dusk is great, Truthear Zero is also fine. Dioko is too lean. Dusk and Oracle, which are near idenitcal, it's enough further up, it makes all the difference.

The Monarch Mk2 does look pretty close but it's still a little higher. I don't find it problematic. But the Diva is also an all-BA set, like the Helios, and I think this makes a difference, the Monarch bass although it doesn't graph THAT much different from the Helios, it's far more present and impactful, I think because it's DD bass.