Flight Mode was working great in 1.9 but in 1.9.4, the charge indicator in the lower right corner flashes from the current number of charges to 0 while flying and flight is constantly turning on and off, so no more smooth flying.

In my tests this seems to be the case on dedicated server (in single player the number seems to always show the correct number). I think I know where the issue is and will look into it today so hopefully later today there will be a build with the fix available for download.

Sorry, I forgot to mention this was on forge-server 1.9.4

A fix would be great, since getting that heart of the storm was a real pain and the flight mode is great (esp. with elytra)

This is turning out to be more difficult than I thought it would be. It's also very different from what I thought the issue was. There was a recent change to forge that makes sense for other parts of the app, but broke syncing capabilities (the thing that I use to store charge) to client. Not completely but enough for rending gale to behave the way you observe it. I am trying to figure out what the fix is supposed to be in this case. May require a fix to forge as well.

I found a workaround for this, might be interesting for othes using reliquary until this is fixed. Setting the number of feathers consumed by flight mode to 0 via xreliquaryx.cfg (cast_charge_cost=0) stops the flight mode from stuttering on/off midair.

Yes that works, but that makes the flight so cheap. I will have a new build on CF shortly, am just in the middle of compiling a changelist so you should have a fix soon.

And this is now released, took quite a bit of time to get reviewed for some reason.