You could toy around with R and KNIME exports either using the generic KNIME ports or just export from inside the R nodes into graphic files, CSV files, .RDS r files, or whole environments .rdata.
Later you could import these files right into RStudio. With .rdata you might save a whole workspace with all results and bring it back into RStudio.
Attached you find some examples:
kn_example_r_export_data_rdata.knar (275.3 KB)
With regards to RServe 1.8.6 - you will have to compile it seemingly. I tried to address several ways to do that in the article you mentioned. You might have to continue trying and see if any one of the ways might help you.