Your request of focus change is huge! I wish my A7s has a setting such that the 55mm f/1.8 FE lens can be set to linear focus instead of logarithmic. Thanks for this request.
Below are all my firmware requests I have for the A7s. If you agree with any of them, I hope you can pass the word :)
Function and Custom customizability of "Silent Shooting Mode" (A7s only)
Function and Custom customization of "APS-C Size Capture"
Function and Custom customization for "Format"
Deactivate Monitor function should turn off the monitor rather than turn the screen black
Improve Timelapse application
Allow linear mode manual focus (instead of logarithmic mode such that manual focus wheel use depends on the speed you turn the wheel)
Fix "Pre-AF" disabled functionality. (When “Pre-AF†setting is disabled, it should apply to both photo and video mode. It currently applies only to photo mode and there is no way to disable pre-af when camera is set to S-AF in video mode as far as I know.)
Allow focus point to be shown when in manual focus mode. (It is useful to know where the focus point is for those of us using AF/MF Control Hold in manual focus mode for video and photography. To remedy this, allow the focus point to be shown when in manual focus mode so that we can use both manual focus mode and back-button focus effectively without having to leave manual focus mode.)