Hi,
I did a test and yes, the translucency seems to be locked to maximum 13 transmissions. I never noticed that. If there is a way to change that, I don’t know it, sorry.
But you still could fake your way around that with a shader mix node with the Tanslucent shader and a Transparent shader as input. Then you cranck up the Transparency Samples.
Maybe it’s just the exposure, which can be adjusted in the “Render Properties tab >> Film panel” or you do it in post, in the compositor with a color correction node.
this material setup is a bit old, but if it suits your needs: Need leaf material that shows that yellow shade in the light - #9 by shajuke
Basically the same material setup, using the Translucent node and Principled BSDF with a Shader Mix on 0.15 for the factor (what ever looks good to you) https://blender.stackexchange.com/questions/173663/best-practice-and-method-for-transparency-with-leaves