When I use glass or ceramic I bake the crust at 450 for 10 minutes or so. I will cover the edges with tin foil or a silicon cover my wife bought me.
I will fill the pie after it has cooled. I stab the bottom with a fork before I precook to keep the bottom flat.
Sometimes I will use parchment paper filled with reusable dried beans.
All depends on crust.

mimics glass or ceramic. I'll try the pre-bake approach along with Warpy's "pie dust" hint. Thanks!

You might want to do a partial prebake to compensate for the amount of time it takes heavy cast iron to heat up The top is cooking while the bottom is sitting in an unheated pan.

Another thing you can try is "pie dust," a light sprinkling of a half and half mixture of flour and confectioner's sugar before you put the filling in, it can sop up some of the moisture that otherwise would have gone into the crust and given you a soggy bottom.

And if you still get a soggy bottom, sigh and think about buying a boring pie tin. The presentation would suck, but maybe the bottom wouldn't be soggy.

Or just take it all philosophically and historically. Pie crust was invented in a time before oven safe ceramic casseroles. A tasteless crust was made and stuffed with a variety of meats and fruits, Savory gelatin was generally poured over all and the crust sealed and put into an oven the bread had just come out of. Such pies were often eaten cold, after the gelatin had set, and the crust was discarded. Any that had sopped up juices and flavoring might have been given to the poor. Mostly, it was broken up and fed to farm animals that would eat it. See? Nobody is meant to enjoy the crust, so your soggy bottom is historically correct. Besides, there's always next year.

say, 10 or 15 minutes at 450*F. I'll also add your "pie dust" recipe before pre-baking just to make sure. I'll also probably need to let the crust cool for a few minutes before I add the custard filling and put it back into the oven at 425*F. Thanks again!

as a seal against moisture while baking the pie.

flavor.

I don't do pumpkin pies, (I prefer making soup from pumping and butternut squash), I make Sweet potato Pies, from an old family recipe. I ALWAYS prebake my pie crust and then, add the fillling and any decoration and/or upper crust.

or baking. It's just half flour and half sugar mixed together. A quick Google search came up with the process outlined on the King Arthur Flour website! Way to go, Dear Bubbie ❤️

https://www.kingarthurbaking.com/blog/2022/11/16/prevent-soggy-pie-bottoms-crust-dust

for about the first half of the baking. Then move it up to middle.

It'll still be a little soft, especially after it sits around for a bit. But well-browned crust lasts longer. I use a Pyrex dish, so I can see the color, but you'll have to guess.

Try blind-baking your crust. I've found that really helps.