I dread shifting issues more thsn any other. Shift feel and funtion is integral to the driving experience, it's part of what sells us on a car, but several problems can cause it to degrade and all too often unless it is something that can very blatantly be demonstrated to a tech or captured on video, it is a HUGE HASSLE finding a dealer that will either try hard to reproduce the issue, or will just buck up, take your word and fix it.
I wouldn't expect those parts to do anything to fix the root cause.
My civic had shifting issues into 2nd. Dealer wouldn't budge. Turns out is was a clutch issue. The CMC was replaced for noise, and the car shifted beautifully for about a month and started going back to where it was. Dealer wasn't buying it. Eventually others in significant numbers started having the issue. One party suggested rebuilding the CMC with parts from older model civic. Tried that, shifted well but started slipping before too long. I adjusted the clutch engagement to the point it would stop slipping and the shifting went right back to its old tricks.
My point is it seems like with transmissions you need to really find the root problem and fix it or you simply will be putting a bandaid on a problem that will keep getting worse. No amount of bushings, shift knobs, fluid, motor mounts, or the other crap people kept suggesting to "improve shift feel" helped. Sure feel improved elsewhere but it didn't fix the root issue and ultimately didn't help.
If the dealer won't play the game I guess you can try the resident Ford rep, take it to a local transmission shop and see if they have insight, or try adjusting your clutch engagement and see if shifting feel improves, that would be pretty damning as far as diagnosing the clutch as the issue.
As for the civic I ended up selling it before the issue was truly resolved. Honda was really awful about fixing issues with their six speeds, not to mention the same flaws persisted for years across different model lines with no fixes. I had friends drive hundreds of miles and stay in hotels or with friends just because their local dealers refused to help and an out of town dealership would fix them under warranty in good faith that there really was a problem and that these customers weren't just inconveniencing themselves to see Honda needlessly fix a perfectly functioning transmission. I really hope should I run into issues like this with my ST that Ford won't disappoint in the same way.
I probably should have taken it third party and had the entire clutch assembly replaced, but I got stupid and wanted different car as well, or so I thought. Hindsight would say should have kept it as my FR-S has been very meh. Live and learn, and spend too much money while you're at it.
Anyway tl; dr diagnose the issue before throwing parts at the problem.
