Great!
i don't know what might successfully secure those down, but as i said before,
i doubt you really have to worry. both my PD-M90X and single-disc audiophile grade PD-91
have these connectors for their front panel PCB CONTROL, and on both i have had to remove them
for repair work, breaking those gray retaining plates along the way.
they have been this way for years now, and have survived a move without fault,
so i'm fairly confident the tension holding those connectors fast is adequate,
providing the players never again have to endure the rigors of shipping or the like...