I'm not sure can or not... shld be can, just another cable to your room.  Try call TM contact centre.

Another way is your friend using vip5, why not top up your portion to upgrade vip5 to vip10 or 20.  simpler.

i did this bandwidth allocation at my home and what i can tell it works flawlessly. i am using the tplink wr841nd and setup the bandwidth allocation to certain computers to only allow certain amount of bandwidth it can consume. like myself, i am using 10Mbps. so what i did i setup my server and my laptop to have full 10Mbps while the rest of the computers only can use 5Mbps. in case you wondering, yeah i did test on all the PC's that i limit the bandwidth and all shows maximum 5Mbps transfer rate while i am getting full speed. i never have slow speed issue since then although my bro's pc keep utilizing the 5Mbps