Humidity!! help me avoid rot and mildew

[dr.thumbgreen]

Hey team

Week 1 flower
Had a crazy rollercoaster of a 1st grow. Underwatering / overwatering and cold roots ,/ tent in general. Have rectified all these issues and plants are super happy and healthy.vpd temp and humidity have all been dialled in and slowly turning up lights since the flip.
Tent is 2.0 x 0.8 x 1.8h
Lights 2 x 4 seasons quantum par 450w currently @60%
Homemade self draining saucers
Homemade dripper system with hydro halos
T8 exhaust running at 30% with controller 69
Thermoforge t7 recirculating for heat
Have a duct to a lung room which is at 40% humidity duct has a 100mm centrifugal fan to boost intake
2 above canopy circulating fans 1 below
Intake is bottom of tent and exhaust is setup with fan and filter outside pulling from top


Have not long had dehumidifier in lung room with centrifugal fan installed and was keeping tent around 55 after a lollipop and defol as i wanted to drop from 65 ish when i flipped. However since the flip started the stretch canopy is thickening again and im unable to get rh under 65 or so. Tent is in ceiling and cold overnight with outdoor environment 100humidity and 3 degrees celcius. My questions are. Do i just make do with what i can and wait till stretch finishes to defol for rh sake and is there another way to lower my rh.

Some photos of the journey appreciate the help