Thanks a lot for your comprehensive answer. Maybe it's easier then to switch the whole printhead instead ? The neo 2 printhead is available around 30 €. Would that be possible? The printhead mounting plate is different, but this I can handle.

That's a mod I was thinking about myself, since I have the parts laying in my drawer already.
Would be more work tho, because you'd have to do the entire re-wiring to an IDC10 connector that then fits the connector of the K2's head.
I'd also only do this when using Klipper tbh, cause there it's much more easy to mess with the offset settings for the probe etc. (Should be possible with the correct g-code commands with the stock fw as well, but I prefer and recommend Klipper anyway.)
In the end it depends on what you want to achieve and how much you're willing to tinker.

Do you need a higher flowrate for printing much faster, or why are you thinking about modding to a Volcano-style hotend?

That's a mod I was thinking about myself, since I have the parts laying in my drawer already.

That would be perfect 🙏, because I'm just beginning with the whole 3D printing thing.

you'd have to do the entire re-wiring to an IDC10

Do you know whether the pinout's for the Neo/Neo2 printhead are documented somewhere ?

I'd also only do this when using Klipper tbh,

Yes I want to go with klipper too, although I have no experience with klipper yet. My mainboards is broken (serial port dead) and since the original mainboard is not sold anymore I want to go with the "Bigtreetech SKR Pico" then. I discovered that on you infosite.

Do you need a higher flowrate for printing much faster, or why are you thinking about modding to a Volcano-style hotend?

Yes, that's my intention. Apart from that the Neo 2 printhead is less bulky and allows a better view onto the printed object.

I'm not going to do it tho, because I also have a klipperized K2 Pro and a few Neo printheads as spare parts, and I really don't need the mod. I personally prefer quality over speed anyway, so I print on the slower side anyway. I usually stick with 100mm/s max with a 0.6mm nozzle, and in most cases I use my old Neo instead of the K2 Pro. Not even sure why lol
There are ways to increase the max flowrate, e.g. increasing the temp, using a CHT nozzle, so you might not even need a Volcano hotend.
Dismounting the head's plastic cover of the Neo helps with getting a better view :)

Anyway, since you said you need a new mobo anyway, you can ofc mod a new head as well. I'd rather install the mainboard with the stock head first tho, get into Klipper and get everything working and then think about the head mod, print necessary parts etc.
Since you wanna use a diff mobo, I'd suggest to think again about certain things:

• Don't get the BTT SKR Pico, get yourself a mobo where you can a) plug in the stepper drivers you want (drivers are NOT soldered onto the mobo) and b) have at least one additional free stepper driver slot, so get one with 5 driver sockets. Then get a RPi (or whatever) additionally that acts as the host running Klipper.
• Don't use the head of a Kobra 2 / Kobra 2 Neo then, use a head of the Kobra 2 Pro/Plus/Max. The difference is that the latter ones already have a LIS2DW acceleration sensor built in, which you could wire up and use for measuring resonances later on. Pretty neat if you ask me ;)

Have a look at this: https://1coderookie.github.io/Kobra2ProInsights/hardware/mainboard/#mod-mks-robin-nano-v31
There I described my mod of the K2Pro with a MKS Nano v3.1, with wiring and printer.cfg. If you get yourself the same board and the head of a K2 Pro/Plus/Max, you can just wire up the head as I did. The rest of the components (x/y-motors, bed etc) you can just connect in the same way as well. You'd have to additionally connect and configure the z-min-limit switch for example and maybe some other things, but then you'd have a working setup with a K2PPM head with built in accel sensor ;)

Whichever mod you'll end up with tho, you might wanna check the total cost of it before attempting anything.
Chances are that you can get a refurbished Kobra 2 Neo or a Kobra 2 for ~100,ドル maybe even less, and that's already about the money you need for a new head and a mobo (plus tools for crimping, some connectors etc.). Then you could use that one and disassemble your Neo to put it in your spare parts drawer.
Both the K2 and K2Neo can be flashed with Klipper right away, no further mods needed and you already have the head you're looking for (without accel sensor in this case tho, but that doesn't matter that much, just get yourself an external one). If you're aiming for higher speed, maybe look out for the K2, since it's dual Z and has those SG15 bearings (which I personally don't really like tho) instead of POM wheels.

..if you wanna talk about it further, feel free to send me an email, so that we don't have to log into GH every time.. ;)