Here is pesak where there’s alot רבנים that a מחיצה has to go by the ohel

Yes it’s some solution, but having engagements with mix men and women and standing in front of holy ohel standing 20 people taking pictures and clapping when the chosen kalla walk out is unheard and not being sensitive which ד אמות we are standing this not only about הפצה this a lack צניעות and especially in such a holy place.

the Ohel is a place of tefila so there should be a mechitza see https://asktherav.com/19276-do-women-also-lift-up-their-hands-when-saying-the-maneh-lashon-also-maybe-there-should-be-a-mechitza-at-the-ohel/

everyone is trying to do hafatzos hamayanos spending so much money etc, here for just making another door (by the 3rd tent) just for men you can bring thousands and thousands to the rebbe! what can be a bigger zchus?

all these stuff weren’t mixed, this in a small skinny 2 ft walkway your pushing together men and woman in the heat of summer….

there is a clear Psak from the Rabonim that there needs to be a Mechitza

All the examples you mention are temporary situations, not fixed arrangements.

Besides, the Rebbe did object to men remaining to watch the chaluka to women.

without giving an opinion on the actual question, just want to point out that the Rebbe’s position on mechitza etc is very nuanced.

on one hand the Rebbe is very strict about mechitzos in shuls etc and even instructing that the kfar chabad seminary should be in kfar chabad beis, not kc proper, due to the yeshiva.

on the other hand, the Rebbe did not shy away from having women appear in public forums where men and bochurim were by design. some examples:
yechidus klolis had 2 tables lined in between the men and women with no full height mechitza (when yechidus klolis was in the Rebbe’s room it was even tighter vdal), oftentimes being an hour long sicha.
dollars in shul downstairs, where bochurim were during the preceding davening (by kuntreisim, the shul was emptied, but not regular dollars), and especially when chassanim and kalos and family would come in, and everyone would sing etc etc.
rallies, when madrichos would come up to the front to get coins from the Rebbe, and in general, after mincha the mechitza was taken down and wasnt a very large separation, especially in the walkways.
lag baomer parades, marching down the street.
purim koton 5738 was a צאתכם לשלום for the shluchim the Rebbe was sending to EY, and the Rebbe specifically asked for the young wives of the shluchim to come down to the farbrengen to get dollars etc from the Rebbe, and this by design includes them somehow getting into the shul and up to the Rebbe while the whole crowd is watching.

again, not weighing in on the specific discussion, but felt that this is relevant, and those who do have an opinion should have the relevant information

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It’s silly to point to how the ohel was before Gimmel Tammuz since there weren’t crowds of men and women visiting the ohel.

The Rebbe was incredibly strict when it came to mechitza, and it’s only write to uphold the Rebbe’s standard at his own ohel.