I paused Smart Charging and now I cannot get it to stop pausing

It may be less than 9 days or even more. It is clear from threads here and Reddit that customers want more control and detailed information on what the criteria are for automatically turning this on. My recommendation is to use the Feedback Hub App and file both a problem report and a suggestion report covering in detail all of the points you raised here.

or we have to wait 9 days for it to take effect

I agree with Barb Bowman which is to drop a feedback through Feedback Hub app about how you want the Smart Charging to work.

I have given feedback through the Feedback Hub - at least a few times.

It's now over a week since I 'paused' smart charging, and it still has not 'automatically' come back on, as I keep being assured it will.

Besides giving feedback, I have reinstalled all my drivers, I have reinstalled the Surface app (which allows me to pause), I have repaired this app and reset it -- and none of that has worked!

I have also spoken or chatted with four Microsoft support people, and none of them have been able to help either.

The last person I spoke with put me on hold for about 15 minutes so she could talk to a Windows person. I asked her: if I can talk directly to them, and regardless, could they tell me what it is - the conditions - that makes the smart charging come back on? And how long should I expect for it to come back on?

After 15 minutes she came back and told me there was nothing she could do, and they had no additional information they could provide for me ....

So, now it's been over a week since I paused smart charging - that I only needed to do for a few hours. And this means my battery has been charging at 100% this entire time - which according to MS, is not good for my battery and will make die prematurely.

So, okay, I'll put more feedback -- and maybe I'll do this a few times a day .... but the bottom line is - give the response that I've gotten so far, I have no hope that anyone is ever going to help me with this.

And I expect that maybe a year or two down the road they'll maybe get to fixing the smart charging system, so that it either works, and/or it gives me the option to turn it back on manually, which they should have done in the first place.

You can also consider enabling Battery Limit mode Battery Limit setting (Surface) - Surface | Microsoft Docs