Agent response on offer deadlines- dilemma

I'm sorry, maybe I should keep these questions about etiquette all in one thread, so please tell me if I'm clogging up the forum.

I just want to ask for more advice:

Say I've got a couple of offers, and I've agreed to let them know on a certain date whether their offers are accepted or not. Now, I'm still waiting on a couple of agents who requested fulls after I informed them of the offers. They said they'd get back to me before that certain date, but there's been no response since, and that date is coming up. Granted, there were only a few days between notifying them of the offer of rep, and the deadline to decide (slightly over a week). (it's a short manuscript, relatively speaking). And there was only one week between sending out the manuscript and the first two offers of rep. So...everything's kinda happening on a short and heightened timeline.

Is it ok to tell the agents who've requested fulls that I plan to accept one of the previous offers? Or it is more polite to wait on the agents who requested, and give them a chance to decide on the manuscript and possibly counter-offer? I could probably ask the agents with offers for a few days' extension, not more. Should I follow up on the agents with fulls?

What's the most polite, non offensive way to go about it?

Thank you so much for your input. I feel quite lost about how to respond professionally without badgering people.

Thanks for the advice! I did hear back from the others after a follow up, so the decision was very clear. I'm the kind of person who agonizes over what to have for lunch (even though what I ever really want is sushi, always) so it took some time to gather the strength to send the confirmation email. I hope I'm not jinxing it!

It's a little weird. Even though I'me very happy with my choice, and would have picked the same anyway, I still feel the rejections more keenly than the acceptance. Should I just practice gratitude more?

Thank you! Still ironing the details, but I really hope it works out!