Two-winding transformer loading

As per IEC 60076-1 Rated power of two winding transformer is defined as

“conventional value of apparent power assigned to a winding which, together with the rated voltage of the winding, determines its rated current”

NOTE:
Both windings of a two-winding transformer have the same rated power which by definition is the rated power of the whole transformer.

This mean we may not be able to load the transformer upto its rating since including transformer losses loading on the transformer other winding will be more than the rating of the transformer. This reduces the effective load which can be connected to transformer. Simulation results shows load that can be connected to 25 MVA transformer at unity power factor (24,750 kVA), 0.9 power factor (23,703 kVA). Simulation result also shows the impact of OLTC (23,838 kVA load at 0.9 powerfactor at -5% Tap).

Share your views in the comment about the other factors influencing the effective loading of transformer?