How to properly (quickly) iterate over Reminders using AppleScript/osascript?
I don't have enough reminders to test for speed but give this a try. You can get the 'named' reminders into a list with one step and then coerce that list into your text output with a second. This should be faster than iterating through them individually.
# Find all Reminders whose name contains &quot;Alumni&quot;
set findMe to &quot;Alumni&quot;
set answer to &quot;Maches: &quot;

tell application &quot;Reminders&quot; to ¬
    set names to name of ¬
        (every reminder whose name contains findMe)

set {TID, AppleScript's text item delimiters} to ¬
    {AppleScript's text item delimiters, &quot; --- &quot;}
set answer to answer &amp; names as text
set AppleScript's text item delimiters to TID

return answer