Thermal assistant and cruise climb are two completely unrelated items in the LX
Thermal assistant behaviour is controlled in the Setup | Graphics | Thermal Mode menu (you must also ensure that in your profile in Styler that you have not deleted the first "thermal" page at the top of all the APT, WPT and TSK modes.)
First you need to select the Enabled box so that it comes on, then you need to select the method you wish to use to trigger the thermal page.
You have two options - thermal detection and Switching SC/Var. I use thermal detection to enact the switch automatically. I don't like the Switching SC option because there are times I like to cruise straight with the vario in thermal mode, not cruise mode and I don't want a thermal assistant while cruising.
Anther parameter that is set here is the page zoom for the thermal page. When it switches to thermal page it zooms to this level, when you leave thermal page it goes back to whatever zoom you had on your nav page.
The fourth parameter on this page that is important is the Switch Angle. After how many degrees of turn do you want the Thermal Assistant to display? The lower the number, ie 45 the sooner it will display upon heading change.
For the V80 switch between cruise and climb, these parameters are set in Setup | Vario Parameters
In the AUTO SC box. If you set this box to off, then you must use an external switch (remote stick)
If you set it to GPS then it will change between cruise/climb based on GPS detecting circling (guessing here that the same Switch Angels set above will be used).
G-load will have it switch when the "inertial" part of the vario senses the thermal acceleration.
Then you can set a speed at which it will switch between cruise and climb.
To use the new remote stick for manual cruise climb - set the AUTO SC to OFF as above
Then in Setup | Variometer
on the SC line, select the SC ON/OFF option ( I think - otherwise it is SC Toggle)
Finally, in Setup | Hardware | Remote Stick
Ensure the Front Seat Remote stick is set to LX Nav 6 buttons and the FRONT SC Button is set to SC ON/OFF option (otherwise it is SC Toggle). - I don't remember which is correct.