The “V” prefix is actually optional, so you should just be able to do
Blynk.setProperty(i,propertyLabelString[i],condtionString[i]); // warn condition
There’s also a little-known feature called BLYNK_WRITE_DEFAULT() which saves you having lots of callbacks like this…
BLYNK_WRITE_V1()
BLYNK_WRITE_V2()
BLYNK_WRITE_V3()
etc...
There’s a few coding examples in here if you want to take a look…
Pete.