Is it conventional to use third-person speech when conversing with a monk?
What does good householders, considering his own good prepared samples, think: Which way requires the most sacrifices, mindfulness, patient, skill in many regards and earn the highest merits of them? This will then easy answer good householders question fast and doing well and is only convention for insider, a matter of Sila, and for outsiders place for merits in the sphere of Dana.
And in regard of meritorious deeds it's actually, different when after trade, not importand of what another might prefer.
Of course, a wise monk would fast think &quot;a learned with pleasing behaviour&quot; if good householder speaks in best manners, but whether on likes to use possibilities for merits or for gains, that wouldn't touch a wise monk much aside of possible not seeing ways given to teach.
As for usual monks good householder usually would/could meet, they are not used to representing a field of merits, are merely ashamed and might be high confused if speaking in skilled and venerating manner, as most are actually former followers of marxism, where such seech is regarded as unproductive and time and effort feeding, strong objected toward gains in the world.
&quot;'Please', may my person ask good householder, whether good householder would be able to consider further and deeper on this matter of topic by him, if my person would give further into it in possible more supportive enviroment for such?&quot;

Abhivadanasilissa 
niccam vuddhapacayino
cattaro dhamma vaddhanti
ayu vanno sukham balam.

[Note that this isn't given for stacks, exchange or what ever else world-binding trade but for escape from this wheel]