We have the standard guard the controls on approach SOP which seems reasonable to me.
More bafflingly there's a procedure somewhere - (deliberate vagueness),one of those preference SOP /non SOPs which even the most diligent organisations end up with - which calls for the pilot in the LHS when PNF to select speedbrake if requested by pilot in RHS, then keep hold of it to be reminded of its deployment, then re-stow it on request. The RHS PF can still select and re-stow it if he chooses, A/P in or out - it matters not, but the LHS guy is the one who should hold it whilst it's deployed.
I can see the reasoning given the standard position of the speedbrake lever, instances of brakes being left out, possibly 3 primary control lever groups to be manipulated together (wheel, thrust levers, brakes) - and maybe other things, but it's too close to Captain's hand hovering for my liking. Few day to day scenes rival that for hacking people off.