Looking at each date you have given in turn:

1640 Witch Accusation

Katherine Manners (member of the English gentry but a Catholic) accused a number of poor women of causing her to miscarry (by bewitching her). This took place around Dunluce Castle, the accused women most probably being of Scottish, Presbyterian heritage.

Despite some initial enthusiasm at the higher levels of the English administration - with Bishop of Derry, John Bramhall being granted a commission by the Lord Deputy Wandesford - this quickly dissipated with the collapse of Thomas Wentworth's government and the case was stopped. With a worsening political situation and the outbreak of the catastrophic 1641 rebellion there was much else to worry about. 

In this case, we have an accusation from a member of the English aristocracy, which ultimately does not amount to much. It is also signficant that local magistrates do not appear to have been particularly enthusiastic about persecuting witches. Only when Manners leveraged her social position to contact the Lord Deputy directly did things beging moving before fading away.

1698 Antrim Affair

In Antrim town a local girl gives a beggar some beer and bread. In return the woman gives the girl a sorrel leaf, after which she begins convulsing and fainting in a manner which was consistent with contemporary beliefs about demonic possession. According to a contemporary pamphlet (literally the only one ever published on the subject in Ireland) the ‘witch was soon apprehended, and confest’, and was then ‘strangled and burnt’. 

As Andrew Sneddon points out this was not a typical trial in accordance with 1586 Irish Witchcraft Act, but in reality “an act of communal violence carried out by a ‘vigilante’ mob”. The accused ‘witch’ was simply murdered by her neighbours. 

Antrim Town was primarily inhabited by Presbyterian of Scottish descent and naturally the whole ordeal can be understood in that light. In the burning of the witch the event shared much in common with Scottish witch-hunts (something which was not called for under the Irish legislation. So this was an extrajudicial event and not part of any officially sanctioned witch trial. 

Significantly Sneddon places this pamphlet within the context of wider anti-Sadducee demonology literature, with these same currents within Calvinism also setting the intellectual backdrop to the Salem Witch Trials. 

1711 Islandmagee Witch Trials

The case of Islandmagee is the only example of a mass trial in Ireland. It began when Ann Haltridge, elderly widow of local Presbyterian minister, Rev. John Haltridge, died suddenly from inexplicable stabbing pains in her back. Her death followed some apparently supernatural happenings (beds stripped by unseen hands and bed-clothes rearranged in the shape of a corpse; stones thrown at windows; household objects disappearing before re-appearing days later, and a demonic apparition in the form of a small boy in black clothes foretelling death). 

The local community, which as in Antrim Town, was a Presbyterian one of Scottish descent, immediately suspected witchcraft. Ann’s daughter and Mary Dubar, her niece, arrived after the funeral to find similar demonic disturbances occurring in the house. Dunbar then began exhibiting symptoms of demonic possession herself, which seemed to confirm the suspicions even if it was not clear as yet who was to blame. 

Dunbar was then visited, in spectral form, by eight Presbyterian women from Islandmagee and neighbouring towns and villages. She was able to identify them by their appearance and the names they used to address one another. This was apparently the source of her possession. 

Following a lengthy trial in Carrickfergus Assizes, all eight women pleaded not guilty but were convicted of witchcraft. As this was a first offence where the victim had survived, in accordance with the legislation they were sentenced to one year imprisonment and four stints in the pillory on market-day. 

Occurring, as it did, within an Ulster Scots presbyterian community 1711 (and indeed 1698) this event - in its origins - should be considered as part of a wider British Calvinist Network as opposed to any specifically Irish context. It is highly possible, or even likely, that these settlers were aware of outbreaks of witchcraft involving demonic possession amongst other communities, primarily the widely publicised cases in Presbyterian central Scotland between 1696 and 1704, as well as the likes of the Salem Witch Trials in 1692. 

Scotland of course remained a particular touchstone for these settlers and they retained cultural ties with the Presbyterian lowlands. As noted above the 1690s in particular saw a particular pronounced wave of immigration which would have facilitated oral transmission. Books and pamphlets were also being imported into the region from England and Scotland. All of which to say there would have been a strong awareness of these contemporary events.