Should consider how monoclonal and polyclonal populations impact this score
The best measures for calibration are Biacore analysis of recombinant antibody and antigen, also gives you k-on and k-off.
Receptor abundance
Surface receptor levels could be measured explicit using CITE-seq with an antibody for heavy chain, which typically don't affect antigen binding (there's a name for these kinds of antibodies, Mia/JC use it).
Could be predicted by BCR/TCR mRNA abundance
Staining protocol
Ex vivo staining (e.g., LIBRA-seq and AVID-seq), done at 30 minutes at 4C.
In vivo staining. I'm trying to convince somebody to do this, basically immunize mice with e.g. HEL-psDNA and score MD4 B cell acquisition levels.
Issues to consider:
Antigen-receptor affinity
Receptor abundance
Staining protocol