We only have two parallel holes at our home club, close enough so you can accidentally hit into the adjacent fairway, 1 and 10. However, we have a couple more blind tee shots, occasionally we realize someone is "in play" while a ball is in the air.
Like @iacas, I'm hesitant to yell when it seems clear that the ball will miss people. I've seen enough folks move in unexpected directions when they hear "fore", I don't want someone to go the wrong way when startled. I've also seen too many start looking for the ball coming at them, which scares me. I turn my back to the shout and cover my head. I'd much rather take one in the back than in the face.
I'll admit, I've never timed a search, so I don't have data about the impact of the rule change. But I do know that we're made an effort to terminate a search earlier than we once would have, so that's positive. I don't have a real problem knowing that during the COVID times, the Tour professionals will have difficulties similar to mine when they hit errant shots, I have very little sympathy. If you want to find it, hit it where there's short grass.
There's no "right" answer, but I'm fine with 3 minutes. I don't think that too much shorter is appropriate, and I wouldn't recommend going back to 5 minutes.
For regular rounds (which is like 90%+ of my rounds) I arrive 30 minutes before tee time. Check in at the clubhouse then spend the remaining time chipping and putting, mainly focused on how the ball reacts when it lands on the green and speed control of putts. Most of the casual courses I play don't have ranges.
Tournament rounds I arrive 60 minutes before tee time, check in and get range balls. I like to take my time and not be rushed for a tournament round. I'll hit roughly 20-30 balls, no specific order, just hitting a few of each "grouping" of clubs like wedges, short/mid/long irons, then fairway wood and driver. If its a narrow course or I know I will be hitting less than driver off the tee, I'll hit a couple extra 3 woods. Then I chip and putt, same as casual rounds getting a feel for firmness of greens and speed.