This has been a long-time discussion among apeirologists: what is the best version of the Ordinal Collapsing Function: the one where the inaccessible variant ψI covers all ordinals of initial cardinality, or the variant that covers only the fixed points ωα = α?
The difference between the two is that while ψΩ(ψI(0)) with a traditional ICF is ψ0(Λ), and ψΩ(ψI(0)) with a total ICF is ωω or ω (depending on what you conisder Ω0).
The traditional ICF came first because it is easier to define: it was first defined in the 1990s by Wilfried Buchholz. However the Total ICF took longer, with the creation of the χ function (which is identical to the Total ICF's ψI).
Both have their advantages, Traditional ICF keeps it's subscripted Ω's still in use, whereas with Total ICF's they're just sugar for the ψI function. In the end, it doesn't matter if you ask me.
Fun fact: the catching point of the Total ICF and the Traditional ICF is at ψΩ(ψI(Iω))