In a local mayoral election that used IRV, I've seen some candidates tell their supporters to vote for them in every slot. Either those candidates didn't understand IRV themselves, or they didn't want to try to explain IRV to their supporters.
Though with a candidate modification: add 'none of them / no confidence' as a virtual candidate that can never be removed by the runoff processes. If 'NoT' is the winner then the entire election is thrown out and all of the candidates are banned from the re-run.
Computer simulations pretty universally paper over the main problem with approval compared to any ranked-ballot (whether forced or unforced preference) methods by pretending that “approval” has a consistent, cross-voter meaning. (This is an even bigger problem with score-based methods than approval.)
Personally, for simplicity and good enough single winner methods, I prefer Bucklin which is both better than and simpler to explain than IRV, but more critically I prefer minimizing single-winner elections. 5-member legislative districts using a candidate-centric proportional method like STV or the method that has the same relationship to it as Bucklin as to IRV, which AFAIK isn't a named method, would be far superior to any possible system with single-member districts, and basically neutralize districting as a lever for partisan advantage.
Paramount executive elections with a parallel successor (e.g., US Presidential tickets, if they were directly elected, or state Gov/LtGov pairs) can even be made into phased single-winner systems to get some of the advantages of multiwinner systems (not proportionality, but you do get some ability to separate partisan and personal preference in the general election, and to thereby weaken incumbency advantage: basically, use any ranked ballots [0] single winner election for the top spot, eliminate the winner, and rerun the election on the same ballots with the same method for the constitutional successor.)
[0] while I am not partial to them, approval or score systems could be used to; simple FPTP fails because it mean those who voted for the top winner have no voice in the designated successor.