Jr:count and jr:noAddRemove


I just wanted to verify if and how ODK customized the behavior of jr:count
in repeats as were getting some questions about repeat counts in formhub.
I'm trying to figure out whether to match ODK Collect's behaviour in enketo
or not. It seems that:

  1. jr:count is allowed to have a dynamic value but this is only
    evaluated once right when a user reaches the first repeat while traversing
    forward trough the form (i.e. if the count value changes later on, it is
    not re-evaluated and the number of repeats stays the same).
  2. any value for jr:count automatically switches on the
    jr:noAddRemove="true()" behavior even if the noAddRemove attribute was not
    provided (i.e. user cannot add or remove repeats when a count attribute has
    been provided).

Could you please confirm if this is correct?

Secondly, but related to this, are there any plans to add support for the
preceding-sibling:: XPath axis?

Thanks in advance,