As noted, schools do receive all components and easily see the rounding that happened. The ACT/SAT concordance also conveniently provides 4 SAT scores for (most) ACT whole number scores.
I’ve also asked this of two admissions officers and they both confirmed they were smart enough to know an X.5 and an (X+1).25 were different and treated them so.
I’m not clear on how asking a question is “wrong”.