Looking on the internet deeply has found these results:

in waiting is the most popular phrase on the web.

at waiting 1343,000 results on the web	in waiting 18,750,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
I'm not good at waiting. I'm not good at waiting. But I'm no good at waiting so... I don't want you doing anything against your will, but I never was very good at waiting. We're good at waiting. Always waiting on the wind to show up, so you can start work, and I'm no good at waiting. I'm a pro at waiting patiently. Bet you're great at waiting for packages too.	A part of those additional credits has been put in the reserve, in waiting of the submission by the Executive director of the Agency of the plans to make such operations permanent. There is no point in waiting until 2025. She was a lady in waiting, do you know? The situation in Egypt could be adequately described as a revolt in waiting for a revolution. There's no point in waiting. If, Cyril, you do it very quickly, you will see that we have these amazing images of ladies, I guess, in waiting or posing. I just don't see the point in waiting. Among my ladies in waiting?

at waiting

1343,000 results on the web

in waiting

18,750,000 results on the web

More popular!

I'm not good at waiting.
I'm not good at waiting.
But I'm no good at waiting so...
I don't want you doing anything against your will, but I never was very good at waiting.
We're good at waiting.
Always waiting on the wind to show up, so you can start work, and I'm no good at waiting.
I'm a pro at waiting patiently.
Bet you're great at waiting for packages too.

A part of those additional credits has been put in the reserve, in waiting of the submission by the Executive director of the Agency of the plans to make such operations permanent.
There is no point in waiting until 2025.
She was a lady in waiting, do you know?
The situation in Egypt could be adequately described as a revolt in waiting for a revolution.
There's no point in waiting.
If, Cyril, you do it very quickly, you will see that we have these amazing images of ladies, I guess, in waiting or posing.
I just don't see the point in waiting.
Among my ladies in waiting?