Stick position + delay

It should be possible using a couple virtual channels.
How do you want to disable the toggle?

You'll start by using a delay channel to get the value toggle 2 seconds after the rudder reaches 100%.
then you'll use a second channel to latch the previous value. I can tell you how to configure it, but I don't understand how you disable the toggle once it is set.

There may be a more efficient way to do it, but this works:

Virt1: Complex, 3 mixers
Mixer1: Mux = Replace, Src = Rud, Switch = None, Curve = 13 Points (1= -100, 2-12 = 0, 13 = 100), Scale = 100, Offset = 0
Mixer2: Mux = Delay, Src = Rud, Switch = None, Curve = Fixed (Value = 100), Scale = 40, Offset = 0
Mixer3: Mux = Mult, Src = Thr, Switch = None, Curve = Zero/Max (Value = 95), scale = -100, Offset = 0

Virt2: Complex, 2 mixers
Mixer1: Mux = Replace, Src = Virt1, Switch = Virt1, Curve = Zero/Max (Value = 98), Scale = 100, Offset = 0
Mixer2: Mux = Replace, Src = Virt1, Switch = !Virt1, Curve = Zero/Max (Value = -98), Scale = 100, Offset = -100

Virt3: Complex, 2 mixers
Mixer1: Mux = Replace, Src = Virt2, Switch = Virt2, Curve = Fixed (Value = 100), Scale = 100, Offset = 0
Mixer2: Mux = Replace, Src = Virt2, Switch = !Virt2, Curve = Fixed (Value = 100), Scale = -100, Offset = 0

Virt1 creates a delayed channel (value of 40 is 2 seconds) based on RUD with an override if Thr moves
Virt2 creates a trinary channel from Virt1. It will have a value of only -100 when Virt1 is -100, 100 when Virt1 is 100, and 0 anytime else
Virt3 is a feedback channel. It will keep its previous value unless Virt2 is +100 or -100 in which case it will take the value of Virt2

It should be possible to merge Virt2 and Virt3 into a single channel, but I didn't spend the time to try it.

Here's an example model file for the Devo8/Emu (note that I used Ch6, Ch7, Ch8 instead of Virt1, Virt2, Virt3)

you only need virtual3 for the toggle igon. virtual1 and 2 are intermediate stages to get there.
i always set the src before the curve. I'm not sure it'll matter, but there are some weirdness to how the fixed curve works, so I always set it 1st. when in doubt, try the model I provided.

I came up with a slightly simpler solution:
Virt1 stays the same as previously:
Virt1: Complex, 3 mixers
Mixer1: Mux = Replace, Src = Rud, Switch = None, Curve = 13 Points (1= -100, 2-12 = 0, 13 = 100), Scale = 100, Offset = 0
Mixer2: Mux = Delay, Src = Rud, Switch = None, Curve = Fixed (Value = 100), Scale = 40, Offset = 0
Mixer3: Mux = Mult, Src = Thr, Switch = None, Curve = Zero/Max (Value = 95), scale = -100, Offset = 0

Virt2 becomes:
Virt2: Complex, 3 mixers
Mixer1: Mux = Replace, Src = Virt2, Switch = None, Curve = 1-to-1, Scale = 100, Offset = 0
Mixer2: Mux = max, Src = Virt1, Switch = Virt1, Curve = Min/Max (Value = 98), Scale = 100, Offset = 0
Mixer3: Mux = min, Src = Virt1, Switch = !Virt1, Curve = Min/Max (Value = -98), Scale = 100, Offset = 0

Virt3 is no longer needed. This merges the feedback in with the trigger so you only need 2 virtual channels.