It seems to me that we are trying to nail jelly to the wall. We're
talking about poitín (more often spelt the English way) poteen, which
label comes from the Erse poitín - little pot - and which generally
means any spirit distilled illegally using a small pot-still.
'Pot still' is important, as it is a crude but effective way of
concentrating alcohol from the original 'wash' - usually any fermented
solution of sugars and/or starches, and the flavours in the original
wash are represented in the resulting constant boiling mixture of
alcohol and water.
A safer but less flavoursome product can be made on the same scale using
a fractionating column. The result is pretty-well impossible to
distinguish from any other fractionated alcohol whatever the original
sugar used for fermentation of the wash.
Such alcohol (silent spirit) is usually blended with strongly-flavoured
pot-stilled products or flavoured with 'botanicals'. The former (due to
powerful lobbying in Parliament in the 19th century) is permitted to be
called 'Scotch whisky' if a certain percentage of pot-stilled whisky is
used in the blend. Usually this is malt whisky, brewed from the sugars
extracted from malted barley and distilled from the result using a pot
still - not necessaril small.
Rum is made from fermented cane sugar, and gin (usually) from silent
spirit usually made from wheat or maize, and flavoured with 'botanicals'
usually based on juniper berries, but some gins are made from malt
liquor - Barra Gin q.v. and flavoured with other 'botanicals'.
Which confusion leaves us with poitín - true poitín is made from a
pot-distilled wash of fermented grain, malted grain or potatoes, and IME
not flavoured with anything else, unlike the ghastly stuff I bought
recently, which (at an educated guess) is flavoured with carrageen.
It should be noted that even the shape of a pot still can influence the
flavour of the product, as can its size and allegedly, the material it
is made from.
HTH