Please keep in mind that what your examiner wants to see is how safe a pilot you’ll be after you pass your checkride. The planning you do should therefore be a realistic representation of what that will look like.
I don’t research every airport along my route for every flight, nor do I evaluate alternates at all for VFR flights. I do try to keep my route near airports when possible in case a diversion is necessary, and they make great VFR checkpoints too (a habit I picked up before GPS), but I don’t look any deeper than that, nor did my instructors or examiner expect me to.
If something does go wrong, then you quickly decide the best place to divert based on how urgent it is to get on the ground; a fire may have a different answer than a passenger needing a restroom or unforecasted weather ahead, for instance. The examiner will want to see you use all resources available (sectional, EFB, glass panel, ATC, etc.) to make that decision live, like you would on a real flight, not checking an unrealistic canned list of diversion points.
Note that if you planned your route to fly over/near airports (see above), the answer is usually going to be pretty obvious, which is another reason to do that. Worst case, crashing at an airport (which should have fire/rescue services readily available) is probably more survivable than crashing somewhere else.