Macroeconomic models with labor-replacing capital?
The Grundrisse’s “fragment on the machines” expounds on the tendency to universal automation rather famously, without Marx having stripped his more idealistic hopes from his exposition, and without the deadening jargon of Capital’s chapters on the organic composition of capital. It isn’t perfect on the automation of science itself, but that just needs to be reread with science posited as a commodity, AI as fixed capital etc. Nick Dyer-Witheford works in this area last time I checked.

The assumption, or rather observation, of the centrality of a diminishing living component of labour is central to Marxist political economy. Normally it is posited as the OCC critique where transcending this process only exists as a negative, but the fragment on the machines pictures the real possibility of social mastering of social production. In “fragment” Marx goes a bit further than UBI and instead poses universal leisure (relief from labour) due to hyper abundance. This is viewed as a fundamentally political achievement and one not achieved by parliament, treasury or finance ministries.

As far as formalisations, OCC seems to be an accepted category amongst the analytical Marxists (Basu 2018 …Ground-rent… [working paper] https://scholarworks.umass.edu/cgi/viewcontent.cgi?article=1242&amp;context=econ_workingpaper). This means it ought to appear in heterodox Marxist economics, as opposed to just Marxist political economy.