What do I lose if I nest before warp-stabilization?

[Elypeco]

So, I'm using premiere 2022.
I'm used to nest before warp stabilize time-modified clips, but today I discovered two things:

1. If I nest a normal clip, the warp stabilization goes much faster (two or three times) vs stabilizing the same clip without nesting.

2. I'm using 4k footage, in a 1080p timeline, h265, with proxies. Normally, when I stabilize, I lose the capacity to see the clips in real time cause the warp deactivate the proxy view, forcing you to work with the original clips. BUT if I nest, and then stabilize, I can see the footage in real time w/o problem.

So, it seems like a no brainer to nest everything that I have to stabilize, time-modified or not.

But this made me think: "This surely doesnt come free". I mean, there has to be a reason for this "easiness" in the stabilization. So... what do I lose when I nest before stabilization? Maybe premiere "thinks" that the footage is 1080 so the stabilization is worse (less pixels to work with)? Or another thing I'm not aware? What really happens to the footage when I nest?

I'm a little lost with this, so any help is welcome. Thank you all!

[Ann Bens]

You basically lose nothing. Nesting sets the clip to 100%.

WS uses the original footage, not the proxies.

[Elypeco]

Ok, it's a relief.
But then... why the difference in proccessing time and the ability to see it in real time?
I'm a little puzzled with that.