I'm not 100% following what's going on here -- which wouldn't be the first time I don't understand my own program

However i will just mention one thing, in FARR there is a help page under Advanced Use / Using Alias Action Keywords:
A new feature with FARR version 2 is the ability to specify alias names in your search string using the + prefix (just like keyword modifiers).
When an alias name is specified in this way, anywhere on the search string, it does not effect search, but it will cause the alias results to be displayed AFTER the result file is selected, with the selected file name as argument $$1 in the alias.
In this way, you can perform a normal file/folder search and then launch a specific alias command with that file/folder as an ARGUMENT.
For example, you could create an alias named hexedit
whose result contents are:
C:\Program Files\HexEditors\HexEdit.exe "$$1"
Now you can type in your search (where mydocsearch is something like "C:\Users\myfile.txt"):
mydocsearch +hexedit
As you type mydocsearch words, FARR will let you search for files as normal.
After you choose the result, instead of launching the result file, you will be presented with
C:\Program Files\HexEditors\HexEdit.exe "SELECTEDFILE"
Which you can then launch.
NOTE:
You can use the same keyword for both alias names and search/scoring keyword modifiers.
This is specifically to let you use +keyword to open files that you have found using a non-default program.
The key thing here is that you define an alias as normal, using $$1 for the file to be opened, but then instead of triggering the alias normally by typing its name first, you use +aliasname in the search.