Do you want the short or long answer??
Short: No, never, ever ever.
Long: Here is the reality of the Sui Lum Tao, some people do it quickly because they think that they are building speed into their techniques, this is not the main purpose of Sui Lum Tao, first you need to develop the root, which can only be developed if the form is performed in a slow and careful way as it is not the technique you are developing, the hands are only positions, the true power in Wing Chun is developed through the proper development of the "Root" i.e the stance, and I am not simply talking about balance here, This is the specific purpose of the first section of the form, the second section and the third, lays down the fundamental ideas and concepts for the Chum Kuio and the Bui Jee, so they are performed still at a medium pace not as slow as the first, but not rushed through, you must feel the use of the Kim in the stance through each hand as this is the only way you are going to develop well. In terms of rushing through I have this to say, when learnig the SLT you will begin to understand that the structure of Wing Chun revolves around prooper body alighnment and proper relaxation, if you speed through the form like a freight train, you are never going to develop this relaxation and you are never going to buiild the necessary neuro pathways, (wehich are vtally important in Wing Chun).
No intended disrespect to your Sifu, but i am not impressed with his ideas in relation to the Sui Lum Tao.
Now we hit a snag you are under his treaching (i hasten to say unfortuanatly) therefore you need to respect what he is saying, and do what he is saying, so do it, then when you get home perform the Sui Lum Tao slowley and carefully. Dont focus on the technique, that is nto the most important aspect of the SLT, focus instead on the stance and develooping the "root"
Listen I just split up with my wife 2 days ago so I am in the mood to be brutally honest, what a bunch of horses$$t, I believe he got that from Bruce Le's "Bruce Lee Strikes Back from the Grave"
Actually you ask any good actor and thats not the first thing they do, the first thing is they get a general sense of who that chariachter is and work on becoming that charichter. And if we want to use cheesy theatrical euphamism's then heres one for you. To truely learn the Sui Lum Tao you have to become the Sui Lum Tao, you need to walk it, breath it, you have to get "in charichter". In short that is bullsh$$ese for you need to be totally an utterly absorbed by the Sui Lum Tao. Forget about the lines, focus on the energy, the rooting and grounding. In Wing Chun the four areas of development in priority are 1) Energy 2) concpet 3) Structure 4) hands, if you follow this line of reasoning in your development it will hold you in good stead.
I dont kinow your Sifu, and I dont particulary want to know (sorry I know he is your Sifu and everything but it has to be said),I know from your post and his comments where his error lies, and the mistakes in his understanding of Wing Chun is, he has literally taken the four areas of development and swaped them back to front. Keep this one thought in Mind "Wing Chun is a conceptual based system, not a technique based one"