You need to add the Hive specialization techs into the MasterTechSpecializationDefs.XML file - I have already done this plus a bunch of other changes in the old version of my Crusade Mod. I don't like how the Crusade has been "dummed down" to accommodate the" two hour" players and I have moved on to playing other games for now but eventually I will do all the comparisons to 2.3 and 2.31 patches to bring my mod up to date again and playable. But for now you can see how those techs are added into MasterTechDefs.XML, MasterTechSpecialization.XML, and ImprovementDefs.XML. Don't forget to add the Description Txt files for your new tech - they go in the Text folder under mods - you can just add them to the end of the standard text version of the your "modded" XML files. If you scan through my changes I have made a lot of other changes. Only major thing I know I haven't accommodated in my unreleased update to my Crusade mod is Stardock removing I think one of the sets of customized techs for I think synthetics and making them use the appropriate equivalent default techs for Manufacturing/Research bonus techs. (they had done this for several other series of techs already as part of their ongoing "simplification" process in the various Crusade patches)
https://forums.galciv3.com/483257/page/1/#3678910
