I'm not sure about how the floatplane specifics (ie does LMG have direct physical access to the servers hosting FP, the distance between LMG and YT vs FP etc), but its not just LTT that I've been noticing the slow transcoding on for HD videos, as I have once noticed it on videos from JayzTwoCents, Louis Rossman, The 8-Bit Guy, Offline TV, and a few others, but its not an isolated issue with just LTT