How many Moon's Topocentric Conjunction occurs per lunar month? It is clear that only one Moon's Geocentric Conjunction occurs per lunar month, what about the Topocentric Conjunction for a given location?

without scale I can imagine many Topocentric Conjunctions as shown in the pictures below:

yellow disk : Sun
gray disk   : Moon
blue disk   : Earth
yellow box  : Observer's Location
red line    : Conjunction's Line
Let's double-check @barrycarter's conclusion:

Ignoring the rest of the solar system and even the Moon's non-negligible mass, the velocity of the Moon's motion around the Earth is on average roughly 1 km/sec per $v=\sqrt{GM_E/a_M}$ (the vis-viva equation).

The Earth is about 12760 km in diameter, so the Moon traverses the Earth's projection in about 3.5 hours.

A topographic point traverses the Earth's projection in 12 hours with a tangential velocity that's never more than 0.47 km/sec. 

That means that the moon's projected position always "moves" faster than a topographic location, so there can never be more than one topocentric superior conjunction per lunar month. 

Hopefully there will never be any inferior topocentric conjunctions for this Earth at least.