You can never stop trying to improve performance issues related to multipath interference if your goal is perfectly reproduced audio at all times. It's a monumentally difficult problem to mitigate.
To expand on this, it's not just issues related to multipath. It's incremental improvements across the board; performance, function and features. The difference is now with SDR's, and any microprocessor or ASIC based hardware, the OEM can push updates and fixes as fast they can identify and solve a problem, and then code and test the solution. Previously there were incremental hardware mods or upgrades that took longer to resolve and resulted in multiple generations/versions of what was essentially the same model device.