https://wccftech.com/latest-windows-10-update-fixes-gaming-related-performance-issues/

Microsoft has rolled out March’s cumulative updates to several Windows 10 versions. One of these updates addresses the in-game performance issue that was introduced by the last cumulative update (KB4482887) delivered on March 1 to Windows 10 October 2018 Update. KB4482887 was an important update since it enabled Retpoline to improve performance of Spectre variant 2 mitigations (CVE-2017-5715).

It appears users can now finally install that update without having to worry about any gaming related performance lags.