Neville Boyde the writer of many books especially on the V. Waltz asked a German orchestra leader who we all know . Why he is recording Tangos in 4/4 time and not 2/4. The answer was they recorded a disk of 2/4 and had to recall it and re-cut it. The buying public didn't like 2/4. There will come a time that the only 2/4 Tangos will be from the distant past.
Armed with this information I asked a visiting lecturer . What if I have no idea till the music starts playing what I am to be presented with. The answer is so easy. I was told we count every Tango as if it is a 4/4. Which it will probably be anyway.
So I came again. Then how do we manage if we want a Four Step to be followed by a Natural Twist Turn.. We need to be on 3 4 for our first step. Again the answer is easy. Simply stand still fo two beats or do a head flick or better still turn the Four Step into a Five Step.
For those who are still not sure what this is about. If as a class you are starting a move after a Link into a Closed Promenade with the music, It must be on the count of 3 4 and not 1 2. If this is done wrongly you will be completely out of rythm for the rest of the group.

What you describe is no matter of a musical time signature in Tango, because when you hear the music there is no difference between 4/4 and 2/4. A "Slow" count in 4/4 is two beats long, in 2/4 (which you hear in Tango as 4/8) a "Slow" is one beat (see ISTD Ballroom technique). So you are not more or less "off phrase" with any dance sequence in 2/4 or 4/4 Tango.

Serendipity has tried this flawed argument under his various posting names (Don, Quickstep, etc) numerous times over the years, and his posting it yet again only indicates that he failed to learn anything from the past threads - nor is he likely from this one either. But I guess we'll have to give it another try.

So yes, for the record you are absolutely correct that the time signature is an aspect of music notation, not of its performance. Some tango performance will have the patterns of stress more impossible-to-ignore obvious than others, but it's always there for the skilled listener/dancer to utilize.

Serendipity did seem to pick up on that point of treating them all the same way - his mistake is in thinking that there's some formalized difference between them that the listener can identify. Yes, various ones sound different, but that is in no way a reliable reflection of the time signature used on the sheet music - instead its an indication of how the conducter decided he wanted to perform it.