I'm sure there are already a dozen threads like this, but I don't think this angle has been covered yet
Basically in enneagram each type forms around the loss of perception of a particular "holy idea", it is a blind spot. Perhaps this correlates with the ignoring function in socionics:
1 Holy Perfection - Ti ignoring (LSE, LIE)
2 Holy Will - Se ignoring (SEI, SLI)
3 Holy Hope- Ne ignoring (IEI, ILI)
4 Holy Origin - Fe ignoring (EII, ESI)
5 Holy Omniscience - Te ignoring (LSI, LII)
6 Holy Faith - Si ignoring (SLE, SEE)
7 Holy Plan - Ni ignoring (ILE, IEE)
8 Holy Truth - Fi ignoring (ESE, EIE)
The 9th holy idea is Holy Love and is said to be the loss of basic trust, the foundation of the ego. So this particular holy idea could be common to all types, without a distinct socionics equivalent.
Bringing the ignoring function into consciousness in socionics causes one to grow, this would be the same as integrating to your security point in enneagram.
so an EIE for example grows when they become conscious of their ethical attitudes (Fi), rather than letting them run on instinct, intregrating from enneagram 8 to 2
Perhaps the role function develops to compensate for the loss of perception of the holy idea (which is not really lost, only fallen into unconsciousness)
So for example an EII, having lost perception of holy origin (Fe - that everything comes from the same "stuff") compensates with Holy Truth (Ti), having confidence in the order of things.
ILE compensates for the lost perception of a holy plan (Ni), with holy will (Se), having confidence in the natural actions/will of forms
IEI compensates for the lost perception of holy hope (Ne) with Holy faith (Si), having confidence in the essential stability of things
LSI compensates for the loss of holy omniscience (Te) with holy truth (Fi), having confidence in the underlying unity of all things