You mean the thing I did a hacky fix for in 4.19? (Fix is there so that it will force flex into the build) I think it might have been a new addition to Flex on 4.19 but regardless if you just let VS bypass that one section, most of the integration would still work. It would just remove some additional editor tooling I think (I tried on the new flex branch too and it does it there too, it compiles but I think it leaves small parts behind by default).