The problem with linear polarizers on cameras is not whether they are film or digital cameras. The problem arises from the fact that light reflected from a dielectric surface can be partially polarized (without using a polarizing filter). In fact early polarizers were just stacks of glass at angles that polarized the light.

Since light can be polarized on reflection, and since autofocus systems on cameras depended on light that was bounced around from mirrors and through various prisms to the autofocus sensor, the use of polarized light meant that the light that reached the autofocus system could be polarized in a different direction from unpolarized light that entered the camera. That could potentially cause errors in the autofocus system.

Using circularly polarized light mitigates this problem because circularly polarized light does not change polarization direction on reflection. That means that it acts like unpolarized light when it comes to the autofocus system. But since the outer half of a circular polarizer is a linear polarizer, it affects the light entering the camera just as a linear polarizer would. The second half of the circular polarizer is a quarter wave plate, which produces a quarter wave delay in one of the polarization components coming through the filter. This means the electric vector of the light wave is not constrained to one direction (as a linearly polarized wave would be) but has two components with a 90 degree phase difference, so the electric vector travels in a circular fashion. Hence the term 'circular polarization'. https://www.uglyhedgehog.com/user-page?upnum=3002

Autofocus systems were developed for film cameras late in the film era and digital cameras took them as a standard feature.

I suspect the effect on autofocus systems is small so that a linear polarizer will work on a modern camera. There is the possibility of focus errors, which I have not evaluated. I took a quick look a couple decades ago and didn't see any effect but it was not a real definitive study.

Note that a circularly polarizing filter will act as a linearly polarizing filter if it is reversed. The quarter wave plate will do nothing important to the light, leaving the linear polarizing component of the filter to do all the work.

Your Crown Graphic will work with either a circular or a linear polarizer (my old Speed Graphic did not have autofocus). Linear polarizers may be cheaper, but since circular polarizers are THE thing to use these days, linear polarizers may be in shorter supply (and therefore higher prices) than the circular polarizers.

PS: 'Disturbing patterns' probably refers to Moiré patterns, which arise from patterns in an image interfering with the square rectangular grid of sensors in a digital camera. They have nothing at all to do with polarizers. It is purely a geometric effect. It is not a problem with film because the film grain is arranged in a random pattern.

If I am right, it is a "potato masher" similar to what Weegee used. A 4X5 camera with a rather large flash attached. I do not believe it had an internal metering system. And I am not sure how easy it was to attach a filter to it. If I am correct, one would only need a linear polarizer but a circular polarizer could also be used. And I do not know if one could be modified for internal metering and what such would be and look like. Therefore the answer to the question has to cover "all bases".

...Taking photos was slow because the film was housed it carriers that contained two sheets of film in a plastic or wood frame with a lightproof feature. You had to insert the film carrier under a spring-loaded back that held it tightly against the back of the camera. Then you had to pull the cover out to make the film available for exposure. After taking the photo, you slid the cover back in place, removed the carrier, flipped it over and repeated the process to expose the other sheet of film on the opposite side.

As you can imagine, the photographer had to lug a number of those two sided carriers around along with the big camera, flash bulbs and "D" size batteries. Being a photographer was a lot of work...

That's true of a lot of antique things. I probably bought 10 used tractors over my farm career. Every one cost me more than the original owner paid for the new tractor. Inflation. The cost of a tractor is the maintenance, not the capital. You could probably make a similar statement for almost every antique thingy you use on a regular basis. A friend had a number of antique cars that he drove regularly. He had to maintain a machine shop to do maintenance (making your own replacement parts, including bearings and brake pads).

On the other hand, I had a John Deere model B tractor. They were made from about 1935 until 1952. In the '90s I could still get parts for them. 10 years is old for a car. 50 years is middle age for a tractor.