You can have your cake and eat it to-

  set $monL DP-1.3
  set $monR DP-2
  
  set $ws1L "1L"
  set $ws2L "2L"
  ...
  set $ws1R "1R"
  set $ws2R "2R"
  ...

  workspace $ws1L output $monL
  workspace $ws1R output $monR
  workspace $ws2L output $monL
  workspace $ws2R output $monR
  ...
  

and upidate bindsyms (maybe add a modifier to switch right workspaces..?)

  bindsym $mod+1 workspace $ws1L
  bindsym $mod+2 workspace $ws2L
  ...