Regarding your questions:
1. May I know if there is any max limit for number of elements we can put in connectWith string?
There is no limitation of the elements that you can list as connected lists.
2. Also if we connectWith more elements does it affect the performance of Browser and/or SortedLists and/or Drag&Drop operations?
While the user drags Sortable widget constantly checks what is the drop target element - if the dragged element is not positioned over its own container than the widget starts checking all possible connected targets. That said the widget loops through all connected instances until it finds where the drop placeholder should be positioned. Having large amount of connectedLists will require looping through a larger collection which might cause performance issues in case the amount is really large.
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