By testing, if you’re referring to sprint, jump and so on testing I would recommend against performing resisted sprints in close proximity to the test day. It is my feeling that all intensive training must be of the highest quality and, for taper reasons, obviously be reduced in volume as test day approaches.
The resisted sprints are far more extensive, as you noted, in their training impact, thus, I’d say it would be contraindicated to substitute them for true speed work nearing the test day.