I realize that doesn't help you now, but the three times I've sent devices in to Apple for repair I've gotten them back the next business day. Maybe I'm an outlier on this, but that's my experience at the very least.
I'm also in the category of having never replaced the keyboard and dealt with it by using external keyboard/mice. The amount of hassle and expense of getting the repair done was not conducive to my schedule. That's great that you could spare your laptop for 3+ days. Not everyone can do that.
Each time I had to take it to the physical Apple store (they didn't even offer me the option of a mail-in repair, and when I asked said it wasn't an option) and each time I'd spend a good hour or two talking to the "genius" before they would have it repaired, usually about a week later.
Not so much impressed how the FedEx driver would just toss the box in my front yard late in the evening. I'd find my laptop in the grass as I was going to work in the morning.
This is something I've experienced as well, at least 3 separate times with FedEx. Every single time the estimate changes to an earlier date, the package ends up arriving later than the original date.
The Friday before the Monday which they were scheduled to deliver, I got a delivery exception saying that it was unable to be delivered according to my instructions and that nobody was home. I WAS home, though I was not notified they were coming, and I can't think of a scenario which "inside or outside the gate" does not cover.
On Monday, Tuesday, Wednesday, and Thursday they updated to say it was 'out for delivery', each time updating in the evening to say the following day after they failed to return to my house. It was finally delivered 1 hour after I left for the airport.
Not sure why Apple uses them. Is UPS worse?