Install wix bundle's MSI packages in parallel

Question

We use wix Burn to chain a list of packages that includes some executables and MSI with lots of custom actions and heavy operations.

<Chain>
      <PackageGroupRef Id="NetFx48"/>
      <PackageGroupRef Id="ThirdPartyEXE"/>
      <PackageGroupRef Id="LongRunningMSI_1"/>
      <PackageGroupRef Id="LongRunningMSI_2"/>
</Chain>

Just wandering:

1. Does Windows Installer supports running packages in parallel?
2. What would be the risks of such execution?
3. Can we achieve this using WIX?

Answer 1

1. No. Windows Installer does not support installing MSI packages in parallel.

2. The first MSI package would start installing. The subsequent installs would fail with an error that an install is in progress.

3. Burn will not purposefully fail by trying to execute multiple MSI packages at the same time, so... no?