I was getting some wood from my stash this weekend and found exit holes and powder rings around them in some of my wood, so I have an active infestation. I know I will have to kiln the wood to kill them. I am a hobiest, but I have about 10k bf of lumber stored. I have a few problems that I'm not sure how to handle.

First a little about the wood. It's Cherry, Maple, Oak, Walnut, and pine. It's 4/4 to 16/4 in thickness. Most is about 14" to 36" wide. It's been in the shed from 10yrs to 6 months, and is a mix of kiln and air dried. The PP holes and frass is only in the sap wood of the walnut and oak. no evidence of it in the heartwood of any of the wood.

I have a lot of wood that is green and 4" thick and only milled about 6 months ago. I heard you should wait a few years before kiln drying wood this thick. How do I handle these?

I only have one place to store this wood, in an equipment shed on my fathers farm. I can only guess the bugs will come right back once I bring the wood back. How do I prevent this from happening?

How do I find a kiln operator that will be able to put the mixed lumber and thicknesses in the kiln without ruining it?

Do I have to dry the wood or is heating it up enough? if it is, are there plans for something simple I can build?

I think Bora-Care orTim-Bor might kill them off. Gene the wood doctor may chime in and give you a more detailed approach.

What size are the holes? They could be ambrosia.

Borates are in water. For them to be effective, the lumber would be wetted and this moisture kept for months to allow the borate to penetrate through the wood. A quick treatment gives only surface treatment, and the problem is all the holes inside the piece of lumber.

You can fumigated using a commercial treater or you can use heat (133 F throughout the wood is the current thinking).

You are correct that once treated there is always a risk that the insects can return.

I just had a lift of material fumigated for PPB. I had the convenience of driving a trailer to the treatment co. and they tent the trailer with the load for only about $50.
The treatment they use here is 3 days under cover.
If you kiln to kill bugs you will want to keep all the wood there after in a dry storage not to gain any water. Sounds like you have a lot of material to deal with.
If you have someone tent your whole stash you can leave as it sits if it's all in the same general area. That will probably cost nearly as much as tenting a home I would bet.
I think the grim reality is, if your in an area you have these predators you are looking at a 5~8 year maintenance plan of fumigation. I also have termites, dry wood and Formosan, to deal with. It starts to be impractical to have too much wood with out end use in sight. I am starting to sell "excess" to avoid bug damage and maintenance.
The beetle I deal with usually only hangs out when the wood is green and most often only in the sap wood.

I can't give you info about air drying the 4" thick boards before putting them in a kiln, but if you can heat them to 140 deg F long enough to heat the center of the boards for a few hours, that will kill the bugs, too.