Created an account just to report this.

Whenever display fusion and ffxiv d11 borderless window are both in use, any click within ffxiv will cause stuttering (about 0.25 seconds worth of screen freeze). Seems to occur a few seconds after display fusion startups.
It's severely more noticeable when spamming clicks within the game. Notable: I'm using monitor fading feature so it could be related to not detecting ffxiv as a fullscreen app

Applied this post's settings and "Disable application hooks (this application only)" to fix it.
https://www.displayfusion.com/Discussions/View/v10-beta-20-kills-current-ffxiv-borderless-window-experience-and-forces-full-screen/?ID=71c56789-6681-43cf-95df-05176cce254f

Version: Display Fusion 10.0 steam. *I don't use steam to launch it or ffxiv.
OS: Windows 10 (21H2)
GPU: 3080 TI 144hz monitor
Game: FFXIV direct 11 mode borderless window

Took me a while to be able to test this. After uninstalling and updating there was no issue with stuttering.

My compatibility settings were not restored after loading my previous configuration which was weird but I only had that one rule for FFXIV so it did not matter.