I am inclined to agree with you.
They were already doing what they were asking for in the FISA warrant. They just needed cover. When it got shot down, and they weren’t finding what they thought, and couldn’t PLANT anything without it being noticed, they went back to the FISA court to cover their tracks again.
I have no doubt that they were looking to PLANT evidence, not find any. Since the polls were going their way, they thought they had it in the bag, and there was no reason to plant evidence.
The other option to consider is that Foreign Intelligence monitored Trump for our Alphabets here. Its done all the time cause our laws are restrictive. We share data, they share data. It would be very hard to track that down then I think.