Sean, I agree with you that the JM spools are tougher to "get going" but all break offs occoured well into the run, i.e. not when the hook was set or at the start of the run when the shock load is highest.
As said, lines got stuck on three and broke on two different reels and I checked the ceramics on the rotor arm with a stocking when checking the guides on both rods. No issues there.
I will not use the JM25k on my Stella 18ks going fwd. I will only use them on my 20k. I have ordered two SOM 25k spools as replacements and will spool them with solid braid. Practising my FG knot as I write...