Dear @Malcolm,
Welcome back to the Wefugees Community and thank you for being such an active member.
I don't see any issue here from the German authorities' perspective (unless the person is receiving jobcenter money and does not share the plans with the jobcenter) as long as the person is also holding a valid travel document. I just know that some governments require a passport validity of minimum 6 months as a requirement for a visa - but that's actually another topic.
Do you agree dear @mbeon-Christine or @mbeon-fardeen with my opinion?
In any case, I recommend to apply for the respective extension of the residence permit as soon as possible as it usually takes some time in these days.
All the best,
Meike