how can i process tag AFTER get_the_content

Hello. I have a plugin that assemble post for me using metafields. This means that i have several
add_filter('the_content','function_name')
that operates metafields structure and creates the post.

The post body itself useless for me – it contains stub (like 111) however final assembled post has <!–more–> tag which is not supported at this level – both excerpt and single post ignores it.

i can handle them myself via own plugin – just strip before/after more tag but i cant difer excerpt output and post output.

i was trying to apply filter to the_excerpt function but seems to be it never hapens – may be i stripped smth from wp core files.

question is: how can i apply the same filter to excerpt and post and be able to make diference one from other in that filter.