XLSForm - Dynamic Selection / Randomizing / Weighted options

Hello Everyone,

I am relatively new to XLSForm, but I'm learning quickly as I come from a CS background.

I'm having trouble setting up this scenario:

Question 1 : (Select-One)
Option 1
Option 2
Option 3
Option 4
Option 5

Question 2 : (Need two unique random picks from a set of options)
Done using splitting options in 2-set blocks and choosing a random number and using filtering
items filter
p1,p2 1
p2,p3 2
p1,p3 3... and so on

Question 3 : (Choose two options from Question 1 for picks from Question 2)

[Constraint 1] : The option that was choosen in Question 1 should have 80% chance of appearing for either of the picks from Question 2, while the other chances are divided among rest of the options)
[Constraint 2] : The same option should not be selected for both

I am currently using select_multiple in Question 2.
I am using select_one in Question 3. And using filtering to avoid choosing the same option. It is still quite buggy.I cannot flatten the select option so that it is always selected without showing radio buttons

What would be the best way to achieve a good result in the above scenario. Once that, I would also like to randomize the options shown in Question 1.