Filling small gaps in deck

[Backyardhockey]

Hello. Cut out a soft spot. Have used penetrating epoxy, 2 coats, from west marine on the edges of the remaining deck. Hard to describe but there are a couple of small gaps, 1/4" x 3", here and there. Once I put the new wood in I will cover with 2 layers of cloth and a load of epoxy. Part of me says forget the gaps because the old wood is firm and after the cloth the whole area will be rock hard. Part of me thinks I should bust my tail back 2 WM and spend $20 for a thimble sized container of filler. And part says a quick squirt of good water-proof adhesive will fill a gap of that size. Any thoughts? If I let the epoxy get a little thick on its own can that fill a small gap? Thanks in advance.