I am using WixStandardBootstrapperApplication in bundle It will install .NET 4.8 and one MSI package, Can find code below,
<BootstrapperApplicationRef Id="WixStandardBootstrapperApplication.HyperlinkLicense">
<bal:WixStandardBootstrapperApplication
ThemeFile="theme.xml"
SuppressOptionsUI="yes"
LicenseUrl=""/>
</BootstrapperApplicationRef>
<Chain DisableRollback="yes">
<PackageGroupRef Id="NetFx48Web"/>
<MsiPackage Id="myMBS"
SourceFile="$(var.Mbs.Updater.TargetPath)"
DisplayInternalUI="yes"/>
</Chain>
Inside that MSI package we have Custom Action to LaunchApplication after InstallFinalize
<InstallExecuteSequence>
<Custom Action="LaunchApplication" After="InstallFinalize" />
</InstallExecuteSequence>
So we don't need to StdBAs bundle to show Success Dialog, How to skip that I have researched but didint find any workable solution
The WixInternalUIBootstrapperApplication was added in v4.0-preview.1 for this scenario where the bundle has 0-n prerequisites and one main MSI. If the prereqs don't need to be installed then only the splash screen and MSI UI will be shown. Otherwise, the prereq BA shows its UI while installing the prereqs and then closes before showing the MSI UI.