By "making upload time much shorter" you mean "making apparent upload time much shorter." They'll still take the same amount of time[1] to upload, except that t

By "making upload time much shorter" you mean "making apparent upload time much shorter." They'll still take the same amount of time[1] to upload, except that that time begins while they're being recorded. [1] Or more, in some probably unlikely cases, for example if the upload speed exceeds the bitrate of the video.