A few comments from an early M2F....
A good tailor will be concerned with providing a good fit, and not with one's lack of a package, and the tailor will do all the tape holding. However, if you plan to pack while wearing tailored slacks, it's a good idea to wear the packer during fitting and when trying on the slacks after tailoring to make sure the fit is true.
As my package came with the rest of me, over the years I have noticed that at completely random times people will turn out to have been checking out my package either intentionally or for any of a hundred reasons that one's eyes might wander that way (BBQ sauce spilled in the lap, or whatever).
If it's any consolation, mine leads to not infrequent discomfort in routine life activities. It's not a dysphoria thing, as much as a "geez, this thing is inconvenient!" thing.