NZXT offers the "GRID," a 3-pin fan controller for about $30. As I thought I understood from reading about the Aquaero 5 and similar, the NZXT also maintains a USB connection with the CPU and system board, providing their own software for managing 30W total spread across combinations up to 6 channels. With the software ("CAM" (??)) you can define fan curves similar to the options with the proprietary AI Suite's Fan-Xpert, Thermal Radar, etc. with Q-Fan. Others would be familiar with Gigabyte's Easy-Tune or similar, successive software.
The key to a product's ability to be on top of fan-management -- 3-pin, 4-pin and combo -- shows in the way it might integrate information native to the board and CPU so as to completely absorb the functionality of the board-maker's proprietary software.
I think if you look, there is also a GRID product that has both PWM and 3-pin outputs. If not -- some accommodation for PWM.
So far, I've been able to avoid a rationalization to try one . . . but I'm lookin' . . .