Do I need a final ultrasound after EVLT?

I think its a good idea to have an ultrasound done not only to make sure the target vein closed but also to rule out any potential complications (although these are very rare).  Having said that, if you are two weeks out and your legs are feeling well, it is very unlikely that anything unusual would be found. 
It is also true, that the remaining veins may continue to improve.

At two weeks you are more than safe to take the compression stockings off and not wear them any longer. If your leg feels better and the veins have become smaller, then the EVLT did work. I still like to do ultrasounds at some point after the procedure to confirm everything looks good.

Yes, an ultrasound examination is a necessity post treatment in order to determine that the targeted vein has been successfully occluded. We scan EVLT patients one week after treatment when they come in for their UGS then we recall them for review appointments and a scan at 3 months, 6 months and 12 months post treatment to ensure that there has been no recurrence.

Although the frequency of post operative DVT/clot following EVLT/RF venous procedures is very low, I still have patients get an ultrasound 4-5 days after the procedure to evaluate the deep venous system.  Especially vulnerable are the venous junctions in the groin and behind the knee where the laser fiber/catheter terminates during the procedure.  Improper positioning of the closure device can increase the risk of a clot in this region. 
I typically have patients wear compression stockings after the procedure for 3-7 days.  If they had a phlebectomy I tend to keep the stockings on longer. I am not aware of any clear data that supports post closure use of compression stockings to enhance the success of the venous procedure or reduce the post operative risk of clot.  Despite this,  I still recommend compression therapy, especially in older less ambulatory patients.

We perform follow up ultrasounds on every patient to make sure that the vein is closed and that the person has not developed a DVT in any deep veins especially near the junction of the treated vein. IF this was already done then yes after 2- 3 weeks it is fine to take off the compression hose and does not need more follow up unless the person continues to have symptoms or other veins need to be treated with sclerotherapy or other treatments

You don’t need to continue wearing the stockings. Only if you have discomfort or pain. I see patients at 1 month follow up. Your veins will continue to improve over time.