I am 99% sure I have ranted on this before...but I am ranting again.
Yes, a Garmin is great for tracking your swim yard!!! Yes, a Garmin can track your times. NO, you should not be hitting the button every time you come in and send off.
As a masters swimmer and a masters coach the #1 observation I have on this topic is in lane 1 and lane 2, the 1:15 and 1:20 send-off lanes, I see 0 as in NO ONE, pushing buttons as they come into the wall or as they send off. What I do see coming in is tough and look at the clock and an underwater streamline off the wall that does not include pushing buttons.
#2 the intervals are tight (when swimming on base or even more on -5) the focus is on swimming not buttoning (new word I made up)
Learn to use the clock and understand your times.
The further down the pool, as in lanes on a slower send-off, the more I see of obsessive Garmin button pushing. Connect the dots...
Sure, use the Garmin to track time and distance!
If you have set you HAVE to remember the times then likely is an all-out hard set and use the "button pushing" effort to streamline and get to the wall faster.
I had a soul-crushing swim set this am. LOTS of ALL OUT, did you get ALL OUT, 25's. I can recall my times for 30 x 2, not each one but I could report back to my coach where I came in for most of them, how I felt