WRT1900AC - Multiple tagged VLANs in single port

I use my WRT1900AC with my french ISP Orange which provides multiple services over different VLANs :
VID 835 : Internet
VID 838 : Sync TV
VID 840 : Streaming TV multicast
...

Like you see, the TV service must be connected to two tagged VLANs, 838 and 840, with priorities respectively fixed to 4 and 5. So I've correctly configured ports 3 and 4 on the router and everything works perfectly.

But, I think this configuration is a waste of ports on the router and 2 wires in the living room is not up with my girlfriend's tastes.

So, I wonder if it's possible to assign the two tagged VLANs (838 and 840) in one unique port on the wrt1900ac.
If it's not possible, maybe Linksys staff will read this post and will add this feature in a future firmware release

PS : sorry for my rusty english...