2.

James Harrington, of Cromwell's government, drafted a plan to make Ireland a Jewish homeland (Panopea is a codeword for Ireland, Oceana for England). Idea was that it would solved both Jewish/Irish problems by replacing the Irish with Jews and turning it into a merchant island.

The Jewish Museum of Ireland gave a talk on it and 18/19th Century Planter Novelist Maria Edgeworth touched on it in a novel to try combat claims she was antisemitic.

James Harrington, The Commonwealth of Oceana (London, 1656).

Fun fact:

The Jewish Rabbi, Menasseh Ben Israel, who backed Oliver Cromwell and succeeded in petitioning to allow Jews re-entry into England, was the teacher of Baruch Spinoza

Menasseh ben Israel's mission to Oliver Cromwell

3.
William Petty (1623 – 1687), Cromwellian land thief and deforester of much of County Kerry, planned an exchange of women between England & Ireland so that the English women would Anglicise the Irish men and the Irish women would be dissolved into the English population.

Source in Pics - Ted McCormick, William Petty and the Ambitions of Political Arithmetic (Oxford, 2009).

4.

An anonymous policy treatise proposed to settle Ireland with Dutch and Flemmings.

Source: D. B. Quinn, ''A Discourse of Ireland' (Circa 1599): A Sidelight on English Colonial Policy', Proceedings of the Royal Irish Academy, Section C, Vol. 47 (1941/1942), pp. 151-166.

5.

Charles Trevelyan, who after his Irish post worked in the Highland and Island Emigration Society, echoed the c.1599 treatise above with his call to replace the Gaels with Germans:

T. M. Devine, The Scottish Clearances: A History of the Dispossessed 1600–1900 (London, 2018), pp. 320-21.

Sept 27th 1662, 'An Act for encouraging Protestant Strangers and others to inhabit and plant in the Kingdom of Ireland' was passed.

It introduced extremely liberal immigration laws to grow the economy, promising that settlers would be "deemed as if they and every one of them had been or were born within this kingdom of Ireland".

"The only condition of the Act of Parliament is that they should be Protestants, and that they should have transported themselves into the country with intent to settle."

Nation-destruction through immigration isn't a new thing.