Agrarian skies - world seed

After reading this question I understand agrarian skies modpack generates the world with nothing in it.

I recently found a world seed with multiple small biomes very close to each other, an ideal world for me.

I want to re-use this world, but start again on agrarian skies (nothing in the world, HQM totally reset, thaumcraft reset, etc.).

I have tried:

• Generating a new world and traveling to the exact co-ordinates of my old world. This seems to have different biomes (due to it being a new seed).

• Copying my old world and attempting to remove all player added blocks manually. (this is far too time consuming, not an ideal solution, though possible if nothing else exists).

• Copying the world and removing the region directory. (this seems to generate a new seed, rather than use the old seed and generate a new world).

Is it possible to generate a new agrarian skies world from my seed so that I have a blank world with all these small biomes?

If not, is it possible to take the old agrarian skies world directory and convert it into a blank one?

Or, is there a command to remove all player added blocks?

Extra info

This is on Agrarian skies multiplayer using agrarian skies v3.1.2 (I think).

I generate the world via the server startup.

Apologies for multiple questions, but I think they all relate to the same problem.

The world seed is 3922357017991451086, if it makes any difference.