As far as I know, the current version of BP (6.4) only requires .NET Framework 4.7. That means BP is only behind .NET Framework versions by 2 minor versions, since the most recent is 4.7.2. I glanced through the changes in 4.7.2 and 4.7.1. I'm no expert but it doesn't strike me as ground breaking changes. I doubt BP will require a .NET Framework upgrade for a while. Now that I've said it, tomorrow they'll announce the requirement to upgrade.
😃
Dave Morris, 3Ci at Southern Company