As another version of .NET, we do need to support this.

However, with v4.8.1, MS made the decision to only allow this framework (and its associated SDK) to be installable on machines running very recent versions of Windows.  This introduces a huge new constraint on our own development environment (which is very complex).  To handle this, we need to buy and configure new servers and do a lot of extra work.

At the moment we're hoping we'll have the chance to build v4.8.1 task runners early in the new year.