Welcome to the forum.
I do not believe the XF16-55mm f2.8 either Mk I or II is parfocal. Or, if one of them are, that feature is never mentioned.
You may find the XF 18-120mm F4 lens is better suited to what you say you are wanting in a lens. It is parfocal and uses a stepping motor rather than a linear motor which will give you smoother transitions when focusing.
https://www.dpreview.com/news/3492623346/fujifilm-xf-18-120mm-f4-lm-pz-wr-lens-is-parfocal-weather-sealed-and-will-cost-just-899