1026.36(g)(1)(ii) states:
Name and NMLSR ID on loan documents. (1) For a consumer credit transaction secured by a dwelling, a loan originator organization must include on the loan documents described in paragraph (g)(2) of this section, whenever each such loan document is provided to a consumer or presented to a consumer for signature, as applicable:
(i) Its name and NMLSR ID, if the NMLSR has provided it an NMLSR ID; and
(ii) The name of the individual loan originator (as the name appears in the NMLSR) with primary responsibility for the origination and, if the NMLSR has provided such person an NMLSR ID, that NMLSR ID.
There isn’t anything in the preamble or the commentary that discusses legal names vs. aliases. I think the conservative approach would be to use the name as it is listed in the NMLS, but if the MLO goes by an alias that is included in their registered information I think you could make the argument for using that as well.