@wlc777 I personally like to have a small - medium, low sided, plastic box or container of some sort to lay a hot pad in covered with a couple towels to help contain puppies as you go. A warm rice sock wrapped in a towel is also an nice addition, and of course make sure puppies are not too hot or too cold. If mom is restless and wants to push standing up, you can help corral the puppies in the box. And after birth if you are doing 2 shifts of puppies to make sure everyone if getting enough milk bar time, then you have a warm safe space for the off shift group of puppies.
As puppies are born, get licked off, and have had a good nurse, I like to put them in the container so I can keep track of who has nursed for sure and help mom focus on the newer puppies who are not dry yet and need time for nursing. The newer puppies also have less competition for colostrum as well, and it keeps space open for on teats, as well as giving mom less to manage as she is also delivering puppies. As long as they are near by and content my girls are fine with this. If a puppy cries, I immediately give it back to mom so my girls know I am helping and not upsetting their puppies. The box is also inside the whelping box, and close enough they can see into the box, and even stick their nose in if they want to check in the puppies in there.
You can roll a bath towel (or two!) long ways to make a "puppy fence" to give them a place to pile up, like a nest. You can use this method during delivery if mom isn't a of puppies in a box, just keeping them a bit out of the way when she is pushing and delivering the next one. My girls will focus more on the incoming puppy if they are not worried about multiple other puppies wondering around and getting upset they are lost, so heated box or "puppy corral" is helpful with larger litters. It also keeps puppies away from the action and messy end...
I also use the "puppy fence" to help keep puppies near mom's belly, but allowing for a sleeping pile of puppies not blocking nipple access for the others. This is really handy with larger litters so you don't have to get up quiet as many times at night to rescue a lost puppy who wondered off. They can crawl over it, but usually they just want to sleep up next to something, either a littermate or the rolled up towel so they don't even try.
I use hot pads under the center of my whelping box to encourage puppies to pile there, but they can move off to regulate their body temps as needed. This also helps keep the puppies in a central spot so mom can lay with her back to the pig rails, as well as get up to move around, or go out then lay back down, without having to dodge puppies everywhere. And then they are conveniently right where they need to be to go nurse no matter what side mom wants to lay on. A heat lamp will usually be warmer in a certain corner, which also works, but I like the centrally located hot pads 2 of them, one hotter then the other, and then the unheated floor space gives lots of options for puppies to regulate their temperature themselves without going too far and getting lost.
I would also keep a calorie supplement gel on hand for mom, I usually mix it with the oral calcium supplement to give after each puppy to keep moms energy level up. I mix it into a large syringe with a thicker blunt tip (they are used for catheters usually - 60 cc/mL syringes) to give her orally, that way if she doesn't want to lick it up I can still make sure she gets enough and easily dispense the amount you want after each puppy in cc's. You can calculate the oral calcium amount you want to give per puppy, then mix with something for sugar and calories and do the math of how many cc's of the mix you want to give per puppy.
She may take a break part way through delivering them, this is pretty common in larger litters. During this pause, let her sleep to regain some energy, if she is calm and content these pauses can last a couple hours without issue. Of course keep puppies nursing to help progress labor naturally. You may need to put her on leash to take a walk if things are slowing down towards the end, of course take a hand towel with you because you never know if she will deliver a puppy on said walk. Feathering is also useful to get things moving, and you said you have oxytocin so that would be a last resort.
I would also highly recommend not letting her eat all of the placentas. Even a few give my girls bad diarrhea, and there is no benefit to eating them. You will be providing plenty of food for her, she isn't in the wild alone in a den and will be going without food for days. Even then, there is a school of thought that since most mothers go throw up the placentas anyways, that they are using their stomach to trasport them away from the den, just like they do to bring food to the puppies later on. There are no beneficial amounts of hormones or anything besides calories in placentas - and you can provide better calories that won't upset her stomach. Frankly, trying to build a milk supply while dehydrated from horrible diarrhea is far from ideal. So try to get the placentas before she does, and keep track of how many she has delivered so you know they are all out at the end.