If Blu-tac is used, the sonic character of the 腳釘 may possibly be eliminated because the Blu-tac would absorb all the vibration. You may try to use Blu-tac alone without the 腳釘 and you should find that using the 腳釘or not makes not much difference in sonic performance.
If you want to keep the sonic character of the 腳釘, you should try to use very thin lining such as velvet paper or a thin plastic film or 保鮮紙, etc
羊皮墊 should be a good suggestion as it combines with 腳釘 to give a different character that you may like. Need to trial to find out yourself. No short cut woo....