No. I am sure that will not work well. The floor stander was made to stand.
As @erik_squires pointed out Martin Logan makes several center channels.
Martin Logan on it's side for center channel ??
since the speaker does not have separate tweeter and mids can I use a full size Ethos on it’s side for a center in HT. I have 13a’s for LR and a ESL c for center but the center is too small , The Ethos panel is 3.5 x the size of the ESL center so would match the 13a's better