That the greatest period of starvation in Ireland’s modern history, during a period of continent-wide unrest had one rebellion with two deaths might suggest that starvation is not the revolutionary impetus you think it is.

That’s fair. In that case allow me to weaken/correct my position: While starvation isn’t the revolutionary impetus, it’s not nothing and does contribute to revolutions.

The food wasn’t there, because some ~90% of the conscripts sent off to WW1 were peasants, in a system that was already in a very precarious position regarding labor and backwards technology being unable to compensate for shortages of labor. Not only that, but WW1 resulted also in the massive buy-up of horses, also key to peasant life and agricultural production. Even in peacetime it was noted that rural peasantry were malnourished, even by the low standards of the Russian working class, and the situation did not improve during the wartime years.

According to historians, the median level of peasant nutrition appears to have stayed normal.

Source. They still weren’t “having the time of their lives,” to correct my previous assertion, but they weren’t going hungry either.

… land-reformers who split with another, more radical socialist party, and who had only marginal support from the peasantry after 1907? How… revolutionary?

Conservative counterrevolutionaries don’t vote for socialist revolutionary parties, which the Trudoviks were. They split with the SRs over the question of whether they should participate in the Duma so they definitely weren’t merely land-reformers. Also where did you get that they had only marginal support from the peasantry after 1907?

Oh great, increased car payments are just an expression of the human desire not to starve too.

I mean yeah why not? If we assume there’s a person X who’s financially in a bad spot, then the reason person X would have issue with the idea of increased car payments is that the money for the car would have to come from somewhere else. Fundamentally there’s not much difference between a working person getting a pay cut (or facing rising food prices) and a farmer having a bad harvest.

Yes, but if the peasantry, who are objectively in a worse food situation than the urban proletariat, are starving, according to your hunger-based analysis of revolutionary impetus, they should be immensely revolutionary.

Were the peasantry in an objectively worse food situation than the urban proletariat? If you have a something supporting that claim please link it.

Yet history shows, time and time again, that this is not the case - and Marx, living during the Revolutions of '48 you claim were driven by hunger, himself noted the lack of revolutionary sentiment in the peasantry.

Peasants didn’t really revolt in the same way urban workers did, and urban workers were absolutely more revolutionary (though in some places the gap shrank with time), but peasant uprisings did happen during in 1848-1849.

Peasant revolts in 1848–1849 involved more participants than the national revolutions of the period. Most importantly, they were successful in bringing the final abolition of serfdom or its remnants across the German Confederation, the Austrian Empire and Prussia.

Source.

Also on the 1848 revolutions as a whole,

Some historians emphasise the serious crop failures, particularly those of 1846, that produced hardship among peasants and the working urban poor.

There’s a reason I said “in part”. I know that the hungry forties were only one contributing cause of the revolutions of 1848, and I don’t think you’ll find a reputable historian that considers them irrelevant.