Using vertical velocity is better than using rolling altitude position because it doesn't lag the target altitude. However, it causes other problems, mainly sloppy altitude control at the target altitude, when the desired vertical velocity is low. Vertical velocity could be used again if a better method can be found that isn't too convoluted.
Reverts Waypoint mode linear climb method back to previous version before https://github.com/iNavFlight/inav/pull/9471.
Using vertical velocity is better than using rolling altitude position because it doesn't lag the target altitude. However, it causes other problems, mainly sloppy altitude control at the target altitude, when the desired vertical velocity is low. Vertical velocity could be used again if a better method can be found that isn't too convoluted.