Welcome back to the Wefugees and thank you for reaching out to us again.
If a person's asylum application was rejected, the time he was holding an "Aufenthaltsgestattung" (during the asylum procedure) will not be "counted" for a later application for a permanent residence permit (Niederlassungserlaubnis).
However, if your friend is holding a residence permit according to section 28 of the German Residence Act now (spouse of a German citizen), he may apply for the permanent residence already after three years holding the temporary residence permit. Please see this website, for instance, for the full list of requirements and further information.
I am not an expert on the Blue Card, but I do not necessary see an advantage in applying for it now. I will link our dear experts @mbeon-Christine and @mbeon-ruth here. I hope they will correct me if necessary and/or add some more information.
In any case, please also don't hesitate to get back to us with any further questions.
All the best,