First, the mandatory quote from the Q&A

:
About the Holly Trinity, I'm not sure when it will flourish, since I know it will be challenging to implement in the grand scheme of things. But I will give it enough time to develop.
Okay, the newly added not-a-kiss with Lena looks a lot like a build up to something special, but I have some problems with that. Firstly it is unneccessary cruel to force players to not have any scenes with Holly if they are interested in her. Secondly if Holly is not with Ian or Lena she will fall to Ivy which doesn't sound so wholesome to me. Lena can somewhat 'protect' her from Ivy but then Holly will stay timid. Finally trying to add Holly to Lena/Ian will remind Lena of what happened with Cherry.
For me it is a kind of toss up. Ian/Holly + Lena means that Holly must be willing to share her newly won prize, Lena/Holly + Ian seems the most straight forward because Holly desperately wants Ian and the gender switch (to Lena/Axel+Cherry) might placate Lena enough to agree and for Lena/Ian+Holly Lena would have to overcome her Cherry shaped trauma (Which she likely will do. Holly did say Lena should talk to Cherry and EvaKiss wrote in the Q&A that 'Cherry's and Lena's stories are tied')
There might very well be multiple paths to the trinity, or at least threesone scenes. I vaguely remember EvaKiss stating it would be very hard to get there but I might be misremembering that because all I could find in the previous Q&A was 'That sure seems like it could happen... if you play your cards right!'
So there is really only one thing I am certain about, you have to get Holly into pole dancing.