I think what's missing is to set which fee (sats/vB) you want to use before sending.

Normally, that is decided by the user before sending.

Even though (or exactly because) it's only for education, I think tx fees is an important detail to understand how Bitcoin works so they should already be included in basic education and not come later as "advanced" knowledge.#

However, I can understand if this makes is too complicated at first. Then the fee should be chosen reasonably. Then you have to decide for the user if he really wants to be included in the next block or if next 3, 5, 20 blocks would also be okay.

Depending on the fee you chose, people can be a bit irritated if it takes too long to confirm or the fee was way more than they expected.