Mine setup capital expenses

Long time lister, first time caller.
Reading through the recent (12 July) resource upgrade, p68/69, there are capital expenses listed for the open pit and underground mine set up:

• A further A$22.6m in pre-strip is estimated for Grants. (I’m unsure what portion of the original has been spent to date)
• Hang Gong capital component is estimated at $45.4m.
• Grants Underground Mining Capital costs: A$13.9 M
• BP33 Underground Mining Capital costs: A$89.8 M
• Carlton Underground Mining Capital costs: A$75.2 M

The 2021 DFS capital expense costs were listed as:

• Grants pre-strip A$33.9M
• Hang Gong pre-strip: A$47M
• Grants UG A$10.3M
• BP33 UG A$4.7M
• Carlton UG A$5.7M

Quite a difference but perhaps I don't understand. Are the UG development costs covered in the All-in Sustaining Cost or do we need to fund these separately? The AISC breakdown in the DFS lists a US$41/t cost for "Sustaining & UG Development Capex" - what does this cover? Either way, the increase in costs is quite substantial. Any insight is greatly appreciated.