The fabric is quite taut, and the lash tab is plastic - I need it rigid to hold my river knife. I've thought about this option - maybe I'll give it a go. I think it might be easiest to pre-punch the holes in the tab before sewing.
However, due to the rigidity of the lash tab, perhaps I should sew over the edge of the tab? (enter through the pre-punched hole, go through fabric just below the hole, exit the fabric just to the outside of the tab, bring the thread over the top and repeat? - sorry if I'm being unclear)