Buying our own modem to use with Comcast - issues with throttling?

[PSPS]

4. I've set up dozens of Comcast accounts and have seen no issues with throttling due to modem type.

The biggest problem Comcast has is their plant (i.e., their wiring along the poles or elsewhere outside.) Many nodes get overloaded, causing large areas to have throughput problems. Increasing the capacity of these nodes can take many months due to the construction required and their accompanying permits. One area where I live has been suffering from this for years, so we switched that location to a fiber circuit from the phone company, but few locations have this option which leaves the inferior DSL as the only option.

Any wireless options that may be available where you live, including 5G, will never be able to provide the performance of a wired circuit like cable, fiber or even DSL.