The safety issue that drove the adoption of ratchets etc on tap-loading sidelevers is that the lever would be accidentally let go of during cocking.

Unlike the underlever, where the support hand will typically be on the grip or back along the stock, away from the flying lever, there is a very real chance that the support hand fingers on the s/l will end up under the flying lever and get chopped off.

Sensible gun handling should reduce the risk to very little.

But even if you have the support hand during cocking in a “safe” position, the torque of the unexpectedly free-flying lever in the scenario above can twist the gun in the hand so that the fingers get in its way. At least for a right-handed user.

These accidents did happen, with e.g. the early Hammerlis after which many later s/ls were patterned.

As a general rule, I very strongly disapprove of deleting any built-in safety feature on a gun. The exception being the magazine trigger disconnector on a Browning GP35 and similar pistols. Not because doing so improves the trigger pull and reload (it does) but because I believe it creates at least as many safety issues as the one that it cures.