How to force re-loading of a section template?

[marekvse]

I have a multi-level templates where the main layout has HEADE and FOOTER sections and the main layout is then used by an actual email template.
I can't figure out (even after looking into the RazorLight code), how to force reloading and re-compiling of the FOOTER for example is I change its content and save it, during which operation I remove that template as well as all the templates that depend on it from the LookupCache using the Remove method.
I'm loading the templates from the database by their ID using the RazorLightEngineBuilder.UserProject(callbackFunction) and that works fine and calls the "callbackFunction" as many times as it needs to load all the dependent layouts. But it does not call the callbackFunction again when I update an included layout and despite removing the cached items. How do I force it to reload the source html/Razor definition again for those templates that are not in the LookupCache anymore?