[PS4] Keyboard input lag / latency issue

Hello all, I'm getting intense keyboard lag while playing with Mouse + Keyboard control scheme on my PS4 launch model. It is up to date at time of writing which is firmware 4.07. Game is obviously up to date as well. I'm playing with display settings set to Full HD with Normal draw distance. I have also set my External Keyboard settings in the PS4 Settings menu to Key Repeat (Delay): Short, as well as Key Repeat (Rate): Fast.

Mouse movement is fine unless I enable extended mouse options in which case it lags behind. Controller input is very responsive. I am playing on a computer monitor so input lag is not an issue from the monitor. It plays PC games and everything else just fine.
I am using both a wired keyboard and mouse, respectively a Noppoo Choc Mini keyboard as well as a Roccat Kone XTD mouse.

Keyboard and mouse work fine in the PS4 web browser with no latency but while playing FFXIV, the keyboard lags behind about 200ms. This is really noticeable when typing out messages.

I initially thought it was a problem with the mouse as the mouse identifies as both a keyboard and mouse since it has function keys. Alas, this is not the issue as I am able to reproduce even without the mouse plugged in. The keyboard is a relatively dumb keyboard (ie. no bells and whistles) and supports PS/2 output, so I don't believe there is any delay with input from the keyboard.

It seems to be an inherent issue with the game itself.