The reason for using m1+le8 instead of stride load + larger group
multipliers is the same as in "[FFmpeg-devel] [PATCH 1/7] lavc/me_cmp: R-V
V pix_abs."

In the test, there is

#define src (buf + 2 * SRC_BUF_STRIDE + 2 + 1)

Therefore, not using e8 will result : (fatal signal 7: Bus error).