Regularly persist to infuse Waterford town with minimalist approach (4,2,4)
I believe the answer is:
less is more
'minimalist approach' is the definition.
I don't know anything about this answer so I cannot judge whether this works.
'regularly persist to infuse waterford town' is the wordplay.
'regularly' means one should take alternating letters (regularly take one letter, leave next etc.).
'to infuse' is an insertion indicator (to infuse is to fill or enter).
'waterford town' becomes 'lismore' (I am not sure about this - if you are sure you should believe this answer much more).
The alternate letters of 'persist' are 'ess'.
'ess' put within 'lismore' is 'LESS IS MORE'.
'with' is the link.
Can you help me to learn more?
(Another definition for less is more that I've seen is " keep it simple!".)