Help dual-classing with EEKEEPER

(original discussion deleted for some reason)
Hi all,
I had planned a Fighter/Assassin playthrough, and only reaching level 7 and trying to dual class I realized that I could not choose a kit.
Then I found the EEKEEPER mod in this same forum, which apparently is able to fix my problem.

However, I also read here that applying kits is not so simple, and at least in older versions also had issues regarding level progression, such as the thief points per level and backstab multiplier being wrong.

I want to ask wether the current version, which I have, still have these issue, and if so, how can I dual class into Assassin and get the correct features (poison weapon, bonus THAC0 and dmg, backstab etc.).