I think that you are a little bit confused with the IRF feature and the Baseline capabilities. The Baseline does not support IRF, as no other stacking feature. The 4800G does support stacking using IRF feature when connected through the CX4 10G ports. The switches that supports stacking using the 1G frontal ports are the 4500 and 5500. All the others models (4200G, 4210, 4500G) does support a "cluster-like" stacking.
If your intention is to create a network with a ring topology, and connect the 4800G switches using the 1G ports, the feature that you need to enable is the RRPP (Rapid Ring Protection Protocol).
Regards.