Well, I gave examples. Where are yours?
That he doesnt brought examples doesnt automaticly means that his opinion is wrong.
Using ability depends on the user's will to use it, not on some devil fruit programming.
As far as we know it is! After eaten a DF your Body is "programmed" to the Devil Fruits will. And i think Luffy himself is a good example for it.
How often his body stretches, mostly just for fun, without him being really aware of it.
(Just one example, there are much more like Nami being upset)
Or Buggy.
I dont think that they always have to be fully aware of an attack incoming that their DF powers will work. Its like their Bodys are under influence of their DF powers full time.
I think that Luffys arm stretches when being pulled is an automatic thing, also that Buggy cant be cut, also that every bullet from anywhere fired on an Logia User will just go through.
So its more or less a fully automatic thing. No difference between Logia or Paramecia Users. Your Body has the Shape of your body but has the attribute of the Element your DF Power gave you. Haki or Kairoseki negate it though.
Once you have eaten a DF, you have the power (advantage or disadvantage) full time.
Besides... there was never a Situation stated where a logia User couldnt grab anything or touch anything because he wasnt aware of it or because his DF Power didnt allow him to. But thats two different things.
Being attacked - not be aware - Logia Powers advantage to let the attack automaticly go through.
Touching something - descission - full awareness - thing can be grabbed.
Also i admit, that it is a difference between just being the Person, with the shape of the Person, or transforming into elemental Form for Attack like Aces fire fist, or smokers white strike.