So, answer for subject question is 'yes':
sets frame exposure speed to 1/4 sec, capture speed also changes (1" on display ~ 5" real time ). Playback speed, of course, is unchanged (30 fps) - we have time-lapse movie in camera
Another functions (derived from SetAE_CdsGainValue, can be found on strings "SetCDSGainApex" and "SetPgaGain") allow change ISO during video recording. Of course, AE must be turned off before call it (ExpCtrlTool_StopContiAE).