Thanks for your answer.
So, I first tried your method as described, and it didn’t work - “Direct” was still the only option I had for both SID or STARS.
I then checked if the order of my content.xml file was correct, as suggested in the info of the KBWI addon developer, and it was: at the end of the file, I had
<Package name="watsupsrinivasman-airport-kbwi-baltimore" active="true"/>
<Package name="navigraph-navdata" active="true"/>
After that, I remembered that as suggested in another thread, the airport package should be before navigraph-navdata-base (in the first lines of the file), and not, as stated by the developer, before navigraph-navdata (which happens to be at the very end). Doing this apparently solved the issue.
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<Content>
<Package name="fs-base" active="true"/>
<Package name="watsupsrinivasman-airport-kbwi-baltimore" active="true"/>
<Package name="fs-base-ai-traffic" active="true"/>
<Package name="fs-base-nav" active="false"/>
<Package name="navigraph-navdata-base" active="true"/>
Now, my questions are: why this discrepancy between your suggestions and the developer’s? Also, why is LFSB missing then? It’s because of RW 07-25?
I got that it’s a MSFS issue, still I think it might be useful to have a list of airports whose procedures aren’t shown on MSFS because of these issues, so that we could either download a third party addon or just try to avoid them (without having to discover mid-flight that they have no procedures).