That’s not true, you can use inline choice modifier commands (allow/disable reuse) with inline ifs and selectable_ifs, but the allow/reuse command must come first.
For example, the following is valid ChoiceScript:
*label top
*fake_choice
*disable_reuse *if (true) #1
*disable_reuse *if (false) #2
*goto top
*finish
The following is not:
*label top
*fake_choice
*if (true) *disable_reuse #1
*if (false) *disable_reuse #2
*goto top
*finish