Opinion seems divided on this. I was taught that the follower should (and would) always transfer wt immediately she is placed in the cross, and it had never occured to me that there was an alternative.
I have never danced with a leader who could lead a cross without a weight change as a walking move. Actually, I've danced with a few leaders who I'm sure, if anyone could, they could, but they didn't. Except as a volcada where the leg sweeps in then out again. I've never had anyone WALK me to cross and STAY THERE without weighting the crossed foot.
In fact, the feeling of movement towards her right that creates the follower's need to cross seems to also result in a need to place weight on the front crossed foot, except in off-axis moves like volcadas
I won't say anything is
impossible, but my hunch is that leading in a way that would indicate to cross WITHOUT also resulting in weight going to that crossed front would be a fairly tricky and advanced skill. Attempts to lead it without the follower putting weight on the front crossed foot typically result in the follower not feeling any indication to even cross in the first place.
So without actually having ever felt it, and certainly without being able to lead it, I'd guess that the lead would require some sort of reversal of intention AFTER the follower's leg crosses, but before she weights it. And it seems that might easily result in her coming
out of the cross and trying to step forward, or at least come to "collected neutral" with the left foot free
beside the right. Getting the follower to cross and then
pause in the cross without changing weight would be VERY difficult. Getting her to go
in and out of the cross without changing weight would be easier with proper timing.
However, there are instructors that teach that the follower should have her weight on BOTH feet
equally following the cross and only do a complete weight transfer if it is led as a separate indication after the cross.
Personally, I have not met leaders who expect the follower to do that and they would be surprised if the follower picked up her left foot after the cross. Also, when teaching beginners, I notice that it is far more common for the follower to err by placing NO weight on the crossed foot and attempt to step again with it for the next step resulting in the leader tripping over her because her right leg is in his way or her attempt to unwrap the left one interferes with his movement. The other thing that happens is that the follower puts weight on the front foot as well as the back (as some teachers instruct) but then doesn't remember (or isn't led) which one she was supposed to be "on" for the next move, while the leader fully expects her to be on her left.
Sooo.... what does all that mean? That clearly leading a cross, while clearly NOT leading a weight change, isn't for beginners? Especially as a part of walking.