ON Semi has elected to obsolete this p/n with better designs.
The advantage of this design is limit the slew rate of charging up current where PWM increases current with voltage feedback as the error becomes smaller with a 1V limit on resetting the SR latch for current sensing.
Yet this also makes it more sensitive to load induced kickback or BEMF when the load steps off from a reactive load and thus might increase the duration of current ramp to cutoff in the opposite direction of what you need for a step down reactive load. I.e. slope compensation.
Instability can occur with integration when the stored energy in the inductor greatly exceeds the demand load causing a need for phase lead compensation (the D in PID control)
As far as your e-field EMI, be sure it is not BEMF conduction noise or else your cables and supply are not well ground shielded. Define your interference induced by radiation or conduction by experiment and report the actual issues that may be causing OCP or OVP shut off on the Is input.
- it could be a design issue from what I tried to explain above, in which case you need more decoupling of the load from the regulated output by of several methods; CM choke, load flyback snubber, RLC damped series load, shielded twisted pairs to load & EMI shielding.
Current and voltage sensing are critical feedback loops that must be tailored to your dynamic load range and acceptable steady ripple voltage. Normally 50% steps are expected but greater steps or driving a nonlinear secondary SMPS can cause issues that demand details, which sometimes maybe be fixed by ultra low small ESR output caps near load.