"It's boring"
Here's the objection with the most truth in it. The form is boring. Filling it in is a dull four minutes, and your evening is yours, and you'd rather not.
Piers Steel, in 2007, pulled together nearly seven hundred correlations from the research on putting things off and asked what predicts it. Personality traits like anxiety and rebelliousness barely did. What predicted it strongly was the task. How unpleasant it was, and how far off its deadline was, along with how confident people felt about it and how impulsive they were. The dullness isn't a side issue. It's the main reason the item is in the heap, and the research says so in a way that should make you feel less singled out. Everyone puts off dull things with distant deadlines. That's what dull things with distant deadlines are for.
Fuschia Sirois and Timothy Pychyl, in 2013, put the mechanism plainly. Putting something off is a way of fixing your mood in the short term. The form makes you feel a small unpleasantness, you close the tab, the unpleasantness goes, and the relief is real and immediate. The cost is passed to a later version of you, who has the same form and less time and a fourth reminder. That later version isn't consulted. They're not in the room when the tab is closed.
So the objection is right about the form and wrong about the arithmetic. The form is boring for four minutes. The heap is boring for three weeks. Every time you see the envelope, you have a small dull unpleasant moment, and there are perhaps fifteen of those moments a day, and over three weeks that's several hundred small dull unpleasant moments in exchange for avoiding one four-minute one. The boredom you're avoiding is the smallest quantity of boredom in the whole transaction.
There's also the question of what the boredom is like when you're actually doing it. In my observation, and this is observation, the four minutes are not as dull as the sofa predicted, because doing a thing has a small momentum in it that dreading a thing doesn't. The dull part is the standing up. The form itself is mostly typing, and the last thirty seconds, when it's sent and the tab closes for good, are actively pleasant, which nothing about the heap ever is.
You'll still find the form boring. The rule in chapter 20 doesn't ask you to like it. It asks you to have four boring minutes instead of three boring weeks, and to notice, afterwards, which one you'd have chosen if the later you had been asked.