Do I remember correctly about an unofficial but popular test of "PC compatibility" in the early 1980s? Basically if a machine could run vanilla versions of both Lotus 1-2-3 and Microsoft Flight Simulator, reviewers at the time would declare it as "PC Compatible". (Note that back then, customized versions of popular software were often available on well-regarded machines.) One particular memory is that the DEC Rainbow 100 computer, while superior to clones in almost every aspect, failed this particular benchmark and was deemed by the computer press as inadequate.
Yes, I think you did. E.g. from The Digital Antiquarian:
Having quickly concluded that simply copying IBM’s ROMs wasn’t a wise option, Compaq hired a staff of fifteen programmers who would dedicate the months to come to creating a slavish imitation. ... Instead of relying on IBM’s published BIOS specifications ... the team took the thirty biggest applications on the market and worked through them one at a time, analyzing each BIOS call each program made and figuring out through trial and error what response it needed to receive. The two trickiest programs, which would go on to become a sort of stress test for clone compatibility both inside and outside of Compaq, proved to be Lotus 1-2-3 and Microsoft Flight Simulator.