This is an old topic and the answer is there is nothing out there or being produced that is correct and reliable. If your interest is in simply running longer trains continuously then this would be something to look into, but it may be easier to try to double head your trains. If your into operations, you should think twice about making your cars too roll easy. The frustration is, with no friction, coupling becomes a serious problem. You'll end up having to unrealistically mash the cars together to get them to couple or end up playing bump and chase down the siding.
The idea behind the pointed axles was to reduce the friction of the axle where it meets the bearing hole. Original Gilbert and Lionel trucks simply had a hole for the flat end of the axle to go into. Over time these holes filled with hair, carpet fiber, old oil and grease, and what ever got caught up in them. They also wore making the hole larger. The reason the old tin Gilbert trucks worked better was because only the thin edge of the metal side frame touched the axle. Less surface to surface contact, the easier it moved. To simply insert an eyelet into the axle hole to take up what is missing or ground off of the end of the axle is a waste of time. Your only getting a clean surface which may improve operation for a short time until the hair, old oil and grease and other contaminants work their way into there.
To properly reduce the friction one would need an insert for the axle hole that was tapered at an angle slightly larger than the angle on the end of the axle. Thus allowing only the tip of the axle to ride in the bearing hole, but keeping slop to a minimum. This would reduce the amount of friction between the axle hole and axle as much as physically can be accomplished. No other way will work.
I heard somewhere that someone was working on some very small roller bearing inserts that can be installed after drilling out the old bearing hole and applying a small amount of adhesive to hold them in place. No need to modify the axles. That would be a viable solution similar to real railroads, but at what cost.