I bought a bag of M4 inserts from Amazon (the usual SourcingMap cheap ones) and drilled out all the self tapping holes for the inserts and then put M4 x 12 countersunk small bolts though and they’re holding much better. Also, I can take the tracks out and refit them without weakening the screw fixings.
The Koi maker is on here too, he’s posted some great tutorials on how he does his stuff;
