Static column RAM/mode is for '030 burst mode only, the '040 bursts differently and SC mode will be disabled (=there is no difference between SC and FP RAM for '040+).
AFAIR, there's a problem with an '060 and SC RAM with Kick 2.0 (it fails to deactivate SC mode) but you can easily sabotage SC mode by swapping in a single FP chip into the first bank (Kickstart just tests the first bank only).
Leaving the slow mobo RAM in doesn't hurt because the faster accelerator RAM gets higher priority and is always allocated first. Only when it's depleted mobo RAM will get used.