Sorry: Migration from Aperture 3.6 to Lightroom Classic questions

Oh well, I am maybe the last person to migrate my Aperture (vs. 3.6) photos to Lightroom Classic. I’m currently still running Mac OS 10.13.6 (High Sierra) but am wanting to make this migration and update my OS.

I have followed the advice below about converting all photos to “referenced” versions:
http://lightroomsolutions.com/articles/migrating-from-aperture-to-lightroom-where-do-i-begin/#adjustments

I placed them in a new folder in Pictures outside the Aperture app, with its own name, “Aperture refcd”

per the URL: “If you don’t like that structure or don’t have enough hard drive space, I recommend you use Aperture’s own Relocate Masters command to switch your “managed” photos to “referenced”. You can choose your own folder structure.” [In Aperture 3.6, the equal? command is “Relocate originals for library” —which I used.]

I also took the opportunity with those new “project” subfolders to move some images around and also rename the subs.

Within Aperture, >Show in Finder for an image takes me to the newly named subfolder in the referenced folder. Good.

But then the Lightroom plug-in for Aperture migration seems to only want to look for an Aperture library, i..e.., .aplibrary.

I can “select” my “Aperture refcd” folder but then the plug-in appears to want me to select each of the subfolder projects, one-by-one, and then to specify the images, but I am not allowed to do that apparently.

That’s where I’m stuck. What have I done wrong and what needs changing?

My option 1? Create a new Aperture library and populate it entirely with my referenced files, leaving them as referenced? Steps are unclear to me though.
My option 2? In Aperture 3.6, I see a second command, “Consolidate originals for library” — I could take the referenced files and bring them in to the existing library, but I assume that is just going to duplicate what is already there?

My option 3. Buy Avalanche, assuming it will address my problems.

Thanks very much to those who have been through this successfully.  Sorry to be a late arrival. I have perused other related messages but did not find my answers . . . .

Joe