It seems there is an issue in v2.3a that causes a conflict with redstone ore and ore excavation. I am referencing a previous post from the other author #Funwayguy/OreExcavation#57.
I did not see the issue here so I am posting it. Here is another crash log.
https://hastebin.com/xayifunini.scala

After more examining it simply happens while mining redstone, with or without ore excavation present.
https://hastebin.com/awizirubet.rb
There is a crashlog without ore excavation.

See also manual mining crash https://pastebin.com/9t0SRDgm
and RFTools Builder block w/ quarry card server crash https://pastebin.com/wzshXQ0G

Since we also don't have a single piece of Rhodochrosite on this server playthrough, that's probably the function that is NPE-ing.

Been away for a few days so could not deal with this immediately as I had hoped. On top of that, I was also midway through changing the way recipes worked in the mod, but that nearly done now. As a temporary solution, I have simply removed the downloads for the version with the issue - the only constructive change made was fixing an issue with fission reactor coolers, but I will get a new version out as soon as I can :)

<3 much appreciated, take your time.

Did this end up getting a fix for 1.10.2?

Fixed in version 2.4 :)