Suggestion for free marathon training plan?

Hello everybody,

looking forward to running the Athens classic marathon (mid-November). Unfortunately, the Garmin adaptive plans are up to semi-marathons and the non-adaptive programs, well let's say I did not really appreciate them a lot (have run a marathon and a couple of semi-marathons using the generic, intermediate, cardio-based plans).

Could someone suggest any 4 days per week free training plans, possibly "friendly" to Fenix 6s? Runkeeper/Runtastic used to have some, but they were bought from adidas/asics IIRC and also are no longer free...

I'm using Lactate threshold based cardiac zones, so it would be nice if I had a ready training plan to match them.