Maybe I am not understanding what you want to do but I use org-babel-lob-ingest/org-sbe to execute blocks from other files on start-up like this:
# Local Variables:
# eval: (org-babel-lob-ingest "Template-Loader.org")
# eval: (org-sbe "Init-Template") ;; the name of a block in Template-Loader.org file
I assume this means that org-sbe can see the block names from the other file. But I haven't tested the behavior with #call just executing elisp.