Found a bug in "OPT_B9PS_RationalResources.cfg" that causes both cryogenic tank types and RR tank types not showing up when both CryoEngines and RationalResources are installed. That file should probably be modified like below:
@PART:HAS[#manufacturer[OPT*Division],@MODULE[ModuleB9PartSwitch]]:NEEDS[B9PartSwitch,RationalResources,!Pathfinder,!ModularFuelTanks,!RealFuels]:AFTER[RationalResources]
{
@MODULE[ModuleB9PartSwitch]:HAS[#moduleID[OPTcmd]]
{
SUBTYPE
{
name = LNH3
tankType = RR_CryoA
title = LqdAmmonia
primaryColor = BurntRed
secondaryColor = BurntRed
}
SUBTYPE
{
name = LCO2
tankType = RR_CryoC
title = LqdCO2
primaryColor = WarmGrey
secondaryColor = WarmGrey
}
SUBTYPE:NEEDS[CryoEngines]
{
name = LH2
tankType = RR_CryoH
title = LqdHydrogen
}
SUBTYPE:NEEDS[CryoEngines]
{
name = HLOX
tankType = RR_CryoHLOX
title = Hydrolox
}
SUBTYPE:NEEDS[CryoEngines]
{
name = LCH4
tankType = RR_CryoM
title = LqdMethane
}
SUBTYPE:NEEDS[CryoEngines]
{
name = MLOX
tankType = RR_CryoMLOX
title = Methalox
}
SUBTYPE
{
name = LN2
tankType = RR_CryoN
title = LqdNitrogen
primaryColor = PeacockBlue
secondaryColor = PeacockBlue
}
SUBTYPE
{
name = LOX
tankType = RR_CryoO
title = LqdOxygen
primaryColor = CadetBlue
secondaryColor = CadetBlue
}
}