想法是對的，但是寫的不夠polished，我提供一個version供參考

I would like to sincerely thank XXX for taking the time to introduce this new function to the team which I should have done much earlier. As always, I really appreciate the support that XXX has provided during the development process. I would also appreciate any comments and suggestions from anyone so that I can continue to make it better.

這樣，你的lead的地位就很清楚了，他也得到了支持者的credit，顯示了你的功勞，同時你還顯得很謙虛很positive。。。。