[Avodah] Not wearing tefillin shel yad protector

[Micha Berger]

I just hit this in AhS OC 32:88, and thought to tell the purveyor of
a "how to wear your tefillin" chart. (CC Avodah.)
https://www.sefaria.org/Arukh_HaShulchan%2C_Orach_Chaim.32.88

At the end of the se'if, in kesav Rashi parenthesis, RYME writes:
    יש שאין מסירין התיק של יד מהתפילין גם בעת התפילה, ואין נכון לעשות כן.
    There are those who don't remove the container for the shel yad
    from their tefillin even while davening, and it is improper
    to do so.

I don't know norms of 100+ years ago, but I /think/ cases in those days
didn't include the maavarta, and he is referring to a 7 sided paper box
(no bottom) worn atop the bayis itself. Much like inserts we have now --
but without a hole for kissing / mishmush of the shel yad during Shema.

But is that a "tiq"? What kind of case or bag would people have been
leaving on when wearing their tefillin? (And didn't get removed back
when they unwound the retzu'ah?!)

So, does the AhS we shouldn't be wearing those inserts to protect the
shel yad, or not?

OTOH, "vehaya lakhem le'os" is used to permit putting your sleeve atop
the shel yad.

Mah beinaihu? I clearly don't understand the AhS correctly.

-Micha

-- 
Micha Berger                 Zion will be redeemed through justice,
http://www.aishdas.org/asp   and her returnees, through righteousness.
Author: Widen Your Tent
- https://amzn.to/2JRxnDF