Most people never consider how the horse responds to just the sight of tack or notice if there are Quality Conversations while doing so.
Each part of the interaction influences the mental reasonableness and physical softness that follows.
While the norm (often out of convenience) is to tie the horse while tacking, the degree of bother or concern a horse may have while doing so frequently is suppressed.
I suggest practicing tacking the horse without tying him. The goal is not about getting tacked up.
It is an Opportunity to notice how your horse feels about standing while you are moving around him.