Read until a certain point

Hello
thank you for this amazing plugin.
I searched through the documentation but didn’t find the answer i’m looking for.
I would like to know if there is an easy way to give a non member visitor the right to read a post until a certain point. For example, i would like to give my visitors the possibility to access the articles until the “read more” section, or the 5 first paragraphs or 30% of the content etc …
This would be more flexible than the excerpt.
Does this functionality exist ?
Thank you
Best regards