i'm using
pages look like this:Function PreLicense
ReadINIStr $LicenseType "$PLUGINSDIR\pimp.ini" "Installer" "LicenseType"
IfFileExists "$PLUGINSDIR\license.$LicenseType" +2
Abort
FunctionEnd
Function SwitchLicense
FindWindow $0 "#32770" "" $HWNDPARENT
GetDlgItem $0 $0 1000
CustomLicense::LoadFile "$PLUGINSDIR\license.$LicenseType" $0
FunctionEnd
;Modern UI Configuration
!define MUI_CUSTOMPAGECOMMANDS
#!ifdef LICENSE
!define MUI_PAGE_CUSTOMFUNCTION_PRE PreLicense
!define MUI_PAGE_CUSTOMFUNCTION_LEAVE SwitchLicense
!define MUI_LICENSEPAGE
!define MUI_LICENSEPAGE_BGCOLOR "FFFFFF"
#!endif
!define MUI_DIRECTORYPAGE
!define MUI_COMPONENTSPAGE
!define MUI_ABORTWARNING