What is U+0E46 THAI CHARACTER MAIYAMOK?

[Richard Wordingham via Unicode]

I am having trouble identifying just what is represented by ๆ U+0E46
THAI CHARACTER MAIYAMOK.

My problem is that the grammatical texts that I have state that when the
Thai punctuation mark mai yamok (ไม้ยมก) is used with words, it is
flanked by spaces, a position reiterated by the Thai Wikipedia entry on
the mark at http://th.wikipedia.org/wiki/ไม้ยมก.  It is not clear to me
whether the Unicode character includes those spaces or not.  I have
encountered fonts whose glyph for U+0E46 has so much space on the left
that I believe is intended to give the appearance of a preceding space.

The glyphs in the reference chart appear to be centred, so I cannot tell
whether spaces are incorporated.  It does appear that those who believe
U+0E46 is flanked by spaces between words omit the following space
before Western punctuation marks.

So, does U+0E46 include either of those flanking spaces, and, if so,
which?

A related question is whether dictionary items like "ประดัก ๆ", which
lacks a corresponding simplex "ประดัก", constitute a single word in any
sense relevant to Unicode, the CLDR or ICU.  I think a spell-checker
will work better if they do.

Richard.