I think it's very context-sensitive. I worked for a while in a financial institution in Asia where we used to have an old curmudgeon of a director, who would quite honestly look for reasons to make life difficult for others to satisfy his own shortcomings. I had a colleague who had family in the Philippines and wanted to relocate there to take on a project. Our strategy was to loudly proclaim that whoever ended up with the gig must have crossed someone senior, until my colleague was "reluctantly" sent there to take it on.
I am sure most workplaces are not nearly as toxic as that one was, but ever since I have always been weary of showing my hand unnecessarily. That said, my current director is the complete opposite and would let me dictate anything if I could spin it slightly as a good idea. So, you'd know best the context that your workplace operates in, and the best answer could range from:
- Straight to the point, this is better, I am more productive, 100% WFH
- Somewhere near 100%, and edge towards it, perhaps frame it as a deal - transition to 100% after a year if a certain baseline is met
- Somewhere less near 100%, and then make a show of the lower productivity during office hours (my favourite is: sorry for the late reply/missed call/late update, I got roped into a situation with the sales team when they spied me in the office, substitute for your own office "time sinks")