I agree with everyone else that the POD is unlikely to work.
But instead of fighting it or proposing alternate PODs, lets try to work with it.
First, this probably works better if Methodism isn't seen as a subset of Anglicanism. So maybe your Methodist preachers in Ireland break off from the Anglicans sooner than the denomination as a whole does. In fact, maybe that's why they go to Ireland, because they are having a controversy with the Anglican Methodists and its convenient to them to make tracks.
Despite the obstacles, Methodism does have some conversion potential as demonstrated by OTL. It offers a more direct, experiential religion than the more established sects of the day and it offers a better format for focusing on personal conduct, which also appealed to many.
OTL Methodism appealed most of all to the respectable poor and the diligent lower middle class types. For that reason, and because of the sociology of religious conversion generally, its more likely to succeed in cities and in newly moved populations. So one question to consider is where are the internal migrations happening in Ireland? Where is trade developing? Where is the urban growth happening? That's where the movement is likely to take a foothold. Second, are there rural areas or even urban areas that are underserved by priests and the existing Catholic organization? Once the foothold is in place, that is where Methodist circuit riders will next make inroads (as on the frontier in OTL America).
Next, again based on trends in the sociology of religion, this Irish Methodism will work best if it is perceived as more or less neutral to existing "frozen" religious divides. It doesn't mean that formally scholars would consider it to be neither Catholic nor Protestant. It just means that on the ground people have to experience it as neither "old backwards" Catholicism nor "hateful oppressive foreign" Presbyterianism/Anglicanism. At minimum this means the Irish Methodists are going to have to have a somewhat different approach to Catholicism than the standard English/Scottish one of denouncing the Pope every day of the week and twice on Sunday. It doesn't mean they will be pro-Catholic, it just means that they won't focus on that stuff and will see it as a distraction from the true inner work of salvation. Quite possibly this Irish Methodism will do very well in the north also. Its also possible, even likely, that the Catholic elites would mostly ignore a movement like that for awhile because it would mostly be attracting the lower orders who probably weren't actively religious anyway before and because the movement doesn't seem to be targeted at them.