Decay setting for those who are on the Continuous training plan

Just wondering, would you have the decay setting as no decay or keep it at optimal decay if you are on the continuous plan setting with no target events and not really going for breakthroughs but following a base/polarised training plan? I did have it on No decay, but read somewhere that you shouldn’t keep on it for long periods of time as your signature could potentially get stale.

I split the difference and find Slow Decay works well during a continous plan base/polarised period.