Oh, absolutely, let's all just cling to conventional wisdom and barrel full speed ahead into loose gravel and up steep hills! That's always a great idea. (*sarcasm*)
In all seriousness, there are techniques to scrub off speed without losing control. One is to shift your weight back, which can help stabilize the bike and give you more traction. Another is to use your brakes sparingly and strategically, avoiding sudden stops or skids.
But here's the thing: sometimes, carrying too much speed is indeed a liability. And in those situations, it's not about "threading the needle" or "making do" with whatever speed you've got. It's about recognizing the limits of your bike and your own abilities, and adjusting your speed accordingly.
Personally, I've found that taking a more measured, deliberate approach to technical terrain has served me well over the years. Sure, it might not be as flashy or impressive as bombing down a hill at breakneck speed, but it's a heck of a lot more sustainable - and a lot less likely to result in a painful crash.
So, is it advisable to deliberately shed speed? In some situations, absolutely. Does it go against the grain of what most experienced gravel riders would consider proper technique? Maybe. But then again, proper technique is subjective, and what works for one rider might not work for another.
At the end of the day, it's all about finding the right balance between speed and control, and adapting your technique to the unique challenges of each ride. And if that means scrubbing off a little speed here and there, then so be it. Better safe than sorry, right?