Can you spend a bonus action in the middle of an attack?

Say you’re a Paladin, and you want to cast Searing Smite.

Can I roll my attack, see the result, and decide if I want to spend my Bonus Action on Searing Smite before the outcome is determined?

Taking this a step further, can I do it after the outcome is known (so I know I will hit)?

Relevant quotes from Jeremy Crawford, DnD 5E Development Lead:

  • (1) You make an attack roll. (2) You hit or miss. (3) You roll damage if you hit. "When you hit" happens at number 2.
  • {The quote below} was addressing bonus actions and reactions that have triggers. A bonus action that has no trigger—such as Cunning Action and the misty step spell—can take place whenever you want on your turn (PH, 189).
  • No general rule allows you to insert a bonus action between attacks in a single action. You can interrupt a multiple-attack action with a bonus action/reaction only if the trigger of the bonus action/reaction is an attack, rather than the action.

Crawford’s quotes above are about timing related to things like spending a Bonus Action between attacks, or defining how certain abilities determine when the "hit" is calculated in the damage formula. My question is, can something as general as a Bonus Action interfere with the "steps" of the Attack roll?

We know that something like the Shield spell can directly interfere with these steps (as the spell’s trigger requires an attack that "hits" you, but then the AC bonus applied can then negate that hit from occurring). However, is that specifically due to the Shield spell’s trigger and magical effect, or is it using a general rule?

Other, related questions:

  • Can you use a bonus action from Cunning Action in the middle of an Attack action?
  • Can you use a bonus action between the separate attacks of a spell?