Currently if you try to enter more than 250 or 300 (I forgot what the hard cutoff is), you simply cannot use the Move Off Farm event. The destination pen will be grayed out and unavailable. This does not happen to other events (but I haven't tested every event, I just know it doesnt work for move off farm). 

I believe this is a restriction because of the web browser we are suggested to use (Chrome). If I use this in Firefox it seems to work (But firefox doesn't work 100% with the bovisync.farm website).

We have work arounds such as using protocols but this isnt always a solution for on the fly move off farm events involving many move off farm animals.