I have successfully replaced the battery in my Pixel 4A. Here's what I learned:

The frying pan method of softening the glue worked brilliantly. I put the frying pan on the lowest possible setting on a gas stove for 10 minutes, and my meat thermometer said it had heated to 200° F. I put a paper towel in the bottom of the pan and set the phone face down on the paper towel and left it there for five minutes, all told. The suction cup was worthless, but a razor blade was able to get the screen removal started, and I completed it with the guitar pick.

Everything else was as expected, but one very important lesson: take bolts out and remember which bolt came from which hole. I removed a piece called the motherboard cover, which was held on by seven bolts, and it turned out they were three different sizes. Six were of one head type, and of those six three were one length and three were longer length. 

The battery I bought came with adhesive strips, but I don't think they were the "correct" adhesive strips, meaning there were no pull taps. That's probably not going to be a problem since they also seem to be considerably less sticky, meaning it probably will not require the pull tab technique in order to remove the battery next time, should there be a next time.

Chris.