Thanks for this Wino, it is a fair question because of the confusion about "manure" and relally we need two words for
fresh manure (poo) – needs stacking in a heap
mature manure (compost) – can be spread on soil
They are such different things. As you say, fresh manure does not hold on to all its nutrients when spread as a thin layer on soil, whereas mature (say year old or more) manure behaves like compost and has nutrients which are not water-soluble.
So it is fine to spread mature manure/compost at any time of year. I find that having it on the surface of undisturbed soil definitely promotes earlier growth in spring, especially of spinach and alliums. I see this every year in my dig/no dig experiment. Also back in the eighties I was well known for having the earliest crops of organic growers in south west England.
Another beneficial effect of no dig is that mycorrhizal fungae are undisturbed and all intact, so they can leap into action in spring and help plants find nutrients, useful when soil is cold.
The ony way that fresh manure can bring heat to soil is by having it like a hotbed, underneath and half a metre deep or more, you can see pictures of some hotbeds in This Month.