There cannot be another way without cutting the mid-pan - they may go a step further and tig weld or braze it back in once done. I don't see that mid pan section providing any significant structural value and I'm not worried about it.
Regarding the dial indicator - I have a mount with a strong magnetic base that I just put on the frame rail and arrange the arms so that the plunger is perpendicular to the harmonic damper. Here's a pic with no bearings installed:
View attachment 264304
The pan was off so I just used a large screwdriver to move the crank all the way in (toward the clutch), zero the indicator, and then move it all the way out. I did the same process after installing bearings and spin test but I didn't get a pic. Super easy with the pan off since you can just pry against a journal and a crank counter weight.
I did try to replicate it after putting the pan on, oil in, and run the engine test and it was certainly more difficult to get a good measurement compared to the pan off. Like the guide mentions, I struck it with a large rubber mallet to attempt to move it all the way in, then setup my dial indicator, zeroed it, and used a large screwdriver behind the balancer to pry it out. I didn't have a helper to push the clutch in which may have been a better method. It worked, but wasn't great as I was afraid of prying against the timing chain cover - I'll look for a better pry point next time or get a helper. Either way, you pretty much have to remove the fender liner and washer fluid reservoir to have good access to do the measurement.
I honestly think that it's easier and more accurate to just drop the pan at one of the oil changes to take the measurement. And, yes - getting a baseline for whatever method chosen is most important.
I'll be sure to update here after a week of real driving and at period intervals.
Good luck.