[Laird Scooby]

That's a Parts Monster own brand special - normally they dish out pretty good stuff so i'd say you were just unlucky this time.

Also unlucky in your diagnosis, for the same reason medical doctors don't like people "googling" symptoms of illnesses online as very often they come up with a worst case scenario, it seems you may have done the same and instead of curing the problem, made it worse.

Engines are designed to run rich when cold, there's no Lambda feedback as the sensors don't work until they reach a certain temperature so it's somewhat arbitrary enrichment - this can also lead to misdiagnosis by reading the plugs in a cold engine.

Judging whether a spark is good can also be difficult. If it jumps 1/2" in free air you've got at least 25kV which should be enough to jump 0.6mm in an engine where the pressure is up to about 160-180psi but it needs to be blue in colour to have some strength behind it.

If it's more orange and only jumping say 1/4", you're down to about 5-6kV with not much grunt behind it - unlikely to "make the journey" across the plug gap.