I don’t think that’s true, though it may depend on the make and model - the related service manual should be consulted. Limp mode is intentional and is mostly meant to limit function while sensors may be disabled, compromised or uncertain. There’s a sensitivity to drivetrain timing that narrows as RPMs increase (e.g. approach redline), limp mode seems to mostly use sane defaults for everything to avoid catastrophic failure in that type of scenario.