how to change sen0676 delay response?

The SEN0676 docs don't list any register for response time or filter speed — the Modbus map only covers empty height, water level, installation height, address, baud rate, and range. No tweakable delay parameter.Strong specular echoes converge instantly because the SNR is high. Weak or noisy returns need multiple chirp cycles to average out before the algorithm commits to a distance — that's where the 5-second sulks come from. 
 

configuring installation height/range didn't change it

Three independent confirmations: a 50-minute window where a mast-geometry change (stronger specular echo) made first-poll answers instant — the only such window in ~600 logged cycles; a steady ~75% instant-answer rate on a calm strong-return surface versus multi-second sulks otherwise; and convergence stretching past 7 seconds right at evening condensation onset, exactly the condition their anti-interference filtering exists to fight.

I'm having the same results on a good and tested setup. It seems to be somewhat dependent upon reflection strength as well.