Something to try:
The aircraft.CFG has a selection of simple scalars which are useful for end-users who wish to fine tune virtual aircraft performance to suit the (perhaps) unique qualities of their rig & controller. ( This is the dread of anyone who writes flightsim physics.....the inconsistencies and variables between individual home setups.)
First, go into the Winjeel's root folder, and backup or create a copy of the original aircraft.cfg file. This is a paramount priority.
Then, open the working aircraft.cfg with notepad.
Scroll down and look for the section [Flight tuning] and a bit below, three sections, [Flaps.0], [Flaps.1], [Flaps.2].
In [Flight Tuning], look for "cruise_lift_scalar= 1.0"
In the flaps section, ignore [Flaps.0], it's just setup to position animations. Sections [Flaps.1], [Flaps.2], look for "lift_scalar= 1.00, drag_scalar= 1.00, pitch_scalar= 1.00."
First try approach & landing the Winjeel without using flaps. If the the aircraft follows performance values that seem realistic, then the wing lift values can be left alone. If the aircraft still seems "floatie", you can go into [Flight Tuning], and reduce "cruise_lift_scalar= 1.0", small increments, and save. Retest flight, and decide if you got what you want, or repeat.
If the plane lands, takes-off....stalls as per reality without flaps....then test with flaps. Too much float, too high a stall speed, not enough drag as per deployment angle....then, play around with [flaps.1] [Flaps.2] scalars.
Best of luck....and make sure to back-up the original file before you tear into it.