When the stars are at their periastron they also are passing each other at the greatest velocity and appear to speed up and whip past each other.
The smaller partner star has a massive and incredible elliptic orbit. How did it and they manage to get and keep that sort of orbit?
Eta Carinae's orbital resonance
Is the whole point of the Eta Carinae orbital resonance so that the superstars solar wind (plasma), plasmaspheres, magnetospheres can connect and influence each other?
Eta Carinae's stars orbital resonance video
This video of Eta Carinae including the latest observed periastron looks stunning. How much of it is actually fact rather than mathematical modelling is hard to initially work out. If those 'gas instabilities' are fact then that would be of great interested to the Electric Universe theory.