The same (older) upgrade XML elements that used for MinorUpgrade scenario is used by the Project.MajorUpgradeStrategy member:
Wix# intention was always to provide MajorUpgrade support only. Thus Project.MajorUpgradeStrategy was eventually superceded with the Project.MajorUpgrade directly mapped to the WiX MajorUpgrade element. However the MajorUpgradeStrategy member is still available and there is a small chance that you can modify it to meet your requirements for MinorUpgrade. See MajorUpgrade sample for details.
project.MajorUpgradeStrategy = new MajorUpgradeStrategy { UpgradeVersions = VersionRange.OlderThanThis, PreventDowngradingVersions = VersionRange.NewerThanThis, NewerProductInstalledErrorMessage = "Newer version already installed", }; //------------- project.MajorUpgradeStrategy = new MajorUpgradeStrategy { UpgradeVersions = new VersionRange { Minimum = "2.0.5.0", IncludeMaximum = true, Maximum = "%this%", IncludeMaximum = false }, PreventDowngradingVersions = new VersionRange { Minimum = "%this%", IncludeMinimum = false }, NewerProductInstalledErrorMessage = "Newer version already installed", };