Pourable stringers & Transom?

[Steplift 72']

I've looked at a lot of info on this site, and about every other boating site concerning the pourable fillers for transoms. I've done a couple transoms and hate to put more termite food in the core. I know seacast says their product can also be used as a filler for stringers, but are there any long term examples of this repair succeeding? On some other sites I've seen reports of cracked transoms, then finding the filler separated from the inner and outer skin and pulverized in spots when inspected. I have actually helped build a solid fiberglass transom on a 23 footer and wonder if that isn't the right way to do a forever repair.