why did you choose to model this relatively dated model of Hind 24 rather than its newer derivatives like Mi35m.
Many reasons. The Mi-24V is the one already in EECH, so doesn't need a new 3D-model. I have a lot of data about the Mi-24V, but hardly any about the new models. A few youtube videos isn't enough to model it. And there is so many new models that it's hard to choose which one, and even harder to find information about the specific model, since it's very easy to confuse with all the other new variants. The Mi-24V is the most widely produced and still most widely used Hind-variant. I don't think any of the upgraded models are in service yet. The Mi-24V is used all over the world, and has been involved in pretty much any conflict for the last 30 years, which makes it excellent for those who want to make historic scenarios. It's a legend

Besides it should be a fun challenge flying something so primitive compared to the new helicopters. For those who think EECH is too easy, try doing a SEAD strike with an Mi-24V and its 70s Soviet avionics

If you have moved on to Hind 24, does that mean you have already completed the 3D cockpit of Ka-52 Alligator and I missed it?
The Ka-52 already has a 3D-cockpit from the start.
I noticed another thread on this forum regarding recoding the Apache 3D cockpit you made earlier, I am unclear as to how this is supposed to be better than your version
It isn't better, it's the same. But only the new version will work after the next exe.
where we can download the latest versions of all 3D cockpits completed to date?
There is only one, the Apache-cockpit. So if you've found it then you have all.
are you planning some reworking of the external lod of the Hind and designing the big cannon version?

No.