Hello,thx for your feedback!The only step that was not intended is killing the turrets on the top floor (on the side of the exit door) with the cube.I suppose i should leave it be as an alternate solution or i could add more turrets to make it harder xD.
All the other steps you described were intended,the bounce gel and the cleansing gel were put just for distraction and all other turrets aside from the turrets on the top floor (on the side of the exit door) are intentionally easily to knock out ;)

Done in about 7 MIn.
Used a unintended Solution.
Did not need two cubes.
Did not use Light Bridge. (as Sheilds?)

Solution:
Hit 1st Button
Anti-Grav it to me
put on lower button
went up
used Anti-Grav to get drown Cube (Cube Respawns)
Anti-Grav it to me again
go up to Floor 3 (with the buttons that controll the gel)
used Anti-Grav to get drown Cube (Cube Respawns)
Anti-Grav it to me again
kill turrents on floor 3
Portal to final floor (exit door)
Use cube to knock down turrents on that floor (knock down left, then shield the second knock it down, repeat)
go back get speed gel hit button
RUN
WIN!

If this was not a intended Solution you might want to edit the chamber.