So after almost 2 hours of catching up (Good job by the way! Some very very interesting reads) I have this continual thought running through my head.
Does anyone in W1 and 2 know that Yen is alive still? Why would someone tell Geralt about Yen if they think she's dead? They wouldn't want to hurt their friend/colleague . At the beginning of W2 Geralt starts to get his memory back and Triss tell Geralt on the boat to Flotsam about Yen and Ciri. From there Geralt is slowing recovering his memory of what happened on the Isle of Avalon and only at the very end by Letho does Geralt finally realise that Yennefer is alive. Or did I miss something?
Every ones argues is that Triss was taking advantage of Geralt's amnesia and that she knew about Yen. But if she thought that Yen was dead, why wouldn't she try to seduce the man she loves? And she thought he was dead for the past 5 years! This is why I think Triss gave up at the end of 2 and let Geralt go. She now knew that Yen was alive and that she had no chance and this fairy tale she had be living for the past 18 months was about to end.
Hope this makes sense (again I don't have time to edit it.)

This has been bothering me! Hope someone else has something to add!
This is how I see it.
It doesn't matter to me because Yen was out of the picture and Geralt fell for Triss.
Like I have been saying all along I think their romance and love is true love because with amnesia he was able to develop legitimate feelings for her as himself. She finally had the chance to be loved by Geralt who she was always in love with.
When Triss realize Yen is alive she can not prevent Geralt from going after her because she loves him. She offers to help him throught it all fully aware that she could lose him to Yen. Geralt realizes he has to go looking for Yen after regaining his memories because, he loved her before his amnesia.
However there is a new development (Triss). He's develop feelings for Triss that are just as strong as his feeling for Yen. They seperate and he goes looking for Yen. Obviously Triss is hurt but realizes that she has to let him go.
Where my issue lies is Yen thinking that she can still lay claim even tho she recovered before he did, knew he was alive with amnesia but, made no attempt to look for him. I know Yen fans would probably disagree and say she has a legitimate claim but, think about it, if two lovers suffers amnesia and one recovers first but makes no attempt to locate the other and that other lover was you, what would you think?
After your recovery, how would you feel knowing the person you loved and claim to love you made no attempts to find you during your most vulnerable time?
I know some people claim that it's not realistic for the women to go after or go looking for the man. Honestly I find that arguement to be ridiculous because, in the witcher world she is a sorceress and she is not limited by resources. Also there are no legitimate reasons why a women can not go looking for her lover who is suffering from amnesia.
If you love someone you would do anything for them after regaining your memories to include moving heaven and earth to locate them. However, if you were trying to avoid them, you would probably stay away with the hopes that they wouldn’t remember and come looking for you.
The quote below applies to Geralt and Triss love. After his amnesia.
"If you love two people at the same time, choose the second. Because if you really loved the first one, you wouldn’t have fallen for the second"— Johnny Depp