Due to the rewrite of qrscu.py the lines implementing the use_modality_tag are removed. On line 586 in qrscu.py should be added:
if query.qr_scp_fk.use_modality_tag: logger.debug(u'Using modality tag in study query.') d.Modality = ''
Also the logic for determining the modality_matching (line 704 and further) has been changed. We might consider changing line 707 to:
modality_matching = False or query.qr_scp_fk.use_modality_tag
Btw. I don't know if we had an update or configuration change, but Impax now also responds correctly without "modality at study level". Using above settings both options work for me now (with or without "modality at study level"). We could also remove the option completely, maybe I was the only one suffering from this issue.