I wonder if you could have a compiler that intentionally pads every instruction to use a vector register pair of <value, slow-const>, so that every value gets paired with whatever constant or other expression will cause the slowest execution of that vector instruction and with the maximum latency chain. Otherwise, it does look like the VDIV instructions can have variable latencies based on the data itself (and not just spectre-like speculation issues on the memory access patterns).
From https://uops.info/table.html