Hi @PTRM_Paleo and @nfshoobs,
That is correct, Simple Search can only be configured from Specify 6 at this time. You can remotely connect to Specify 6 and modify the queries run by simple search which may resolve some or all of your issues @nfshoobs!
Simple Search requires the use of wild card characters to be used successfully. For example, searching for ‘amblema*’ returns all taxa and determined Collection Objects to any name in that genus:
https://invertebrates.osu.edu/specify/simple-search/?q=amblema*
Know also that when you are searching for something with a space in the name it is interpreted as two different search criteria. For ‘Ohio River’, you’ll want to put quotes around it:
https://invertebrates.osu.edu/specify/simple-search/?q=%22Ohio+River%22
Responding to the main issue that I believe you both are encountering (spurious synonym results in simple search), this is still being prioritized internally, but I have a solution to remove the always linked taxa.
From what I have gathered, the three Simple Search queries that are always displaying results no matter the search criteria are as follows (name and description from Specify 6):
- Taxon Preferred Taxon – Old Taxa with their preferred names.
- Collection Object Preferred Taxon – Collection objects with determined Taxon names and preferred Taxon names.
- Collection Object Taxon (all synonyms) – Collection objects with determined Taxon and its synonyms
After connecting to the PTRM database using Specify 6, I was able to “deactivate” these three searches so they are not being run every time a query is made:
Once I completed that, I copied the modified Express Search Config app resource from my user into the ptrm user so you will also be able to see my configuration.
For @nfshoobs, the modified ExpressSearchConfig app resource you can add to your user is available here:
modified_expresssearchconfig.xml (25.5 KB)
Now searches with any query no longer result in these erroneous results (screenshot from ptrm):
Note: I’ve added details of this to the GitHub issue
Once this issue is properly resolved, we can re-enable these queries! I hope this makes searching a bit better for you both 
@PTRM_Paleo, this is live in your database now! You will need to log out and log back in to see the changes.