Ireland had Home rule in it's grasp immediately prewar. Now that in itself opens a pandoras box because you had two large powerful militias north and south both read to fight for and against home rule. Britain would've have a real hard time if civil war broke out, what British solider is going to fight against unionists that want to stay as part of the union? what politician is willing to telling the Irish they can't have home rule?
Partition is inevitable, this doesn't change by the Rising. Immediate aftermath the irish response was primarily a negative one towards the Rising, basically a bunch of extremists who had wrecked half of Dublin for no gain. However the British response radicalized the Irish population. Almost a 101 on how not to deal with an insurrection, kill the leaders including a wounded man who can't even stand. Arrest thousands of innocent men and put them in a camp with IRB/IRA members. Should've written a letter to 10 downing street thanking them for the free army.
War of independence was even worse, burning down half of Cork, burning houses, threatening people etc really ended any hope of having the population on side. You get rid of that, exile the leaders or keep them imprisoned rather than kill them. Do less shitty random arrests, don't put innocent men in camps with IRA members. By late war of independence, IRA flying columns were running out of ammunition and supplies. But Britain had lost popular support in Ireland and at home, people were absolutely outraged by the Black n Tans behavior. Classic in any guerilla war, if you don't have support in the country, you lose. Only other way to go was full Boer war, and that'd be an extraordinarily expensive disaster that'd probably destroy Britain's reputation. It's not worth it, it has no support anywhere and it would bankrupt Britain.
Best you can do is Home Rule and partition at least, and more likely and Irish dominion, again with partition. The latter is absolutely possible, just don't be an idiot.
Partition is going to happen, no matter what. Might be reduced to four county, might have some cross border assembly to ensure thing s remain relatively peaceful and overall on good terms.
You want to keep Ireland as part of the metropole proper, governed from Westminster? Good luck.