For a piano piece, I want a sforzando (which I interpret as a strong accent on every note in that beat) to be applied to two beats. Until now I have notated it like this, with sffz between the notes:

I think this is understandable, if admittedly non-standard. However this becomes less elegant to write when the division between those notes falls on the border of a bar:

I'm unsure as to workable alternatives. Writing subito ff and subito mf afterwards feels overwritten. Just replacing it with > accent marks seems somehow weaker, and it would require three marks on the left-hand notes (which should be staccato like the others, and I gave them marcato too because I wish the bass to be slightly dominant).

EDIT: two sforzandos after each other also works, though it looks a bit busy.