If the Pokemon's held item is consumed, and the Unburden boost is gained...

Question

but then you steal the foe's item with Covet...

Then:

A. Will you keep the speed boost?

B. If the speed boost is kept can you further increase the speed boost by removing your item gained by stealing it from the foe?

Answer 1

I just tested this on PO.

The boost will only stay with you when your item isn't there, The second you get an Item back ( I used a Tropius with Bestow to test it ) Your speed goes back down to its original, although when you consume Its item again, your speed goes back to double.