I’ve done some thermal testing of the Reform, and the heatsink is enough to keep the CPU from hitting its throttle point: the peak I measured was about 67°C, using the internal temperature sensor - and it dropped back down to 60°C in the five-minute cooldown period at the end of the benchmark, showing that the case doesn’t trap too much heat.
A common misconception of NVMe hardware is that, like most electronics, it has to be kept cool; in fact, the flash itself needs to be above a minimum temperature for efficient operation. Cool the flash too much, and the controller will actually pump additional power to it in order to warm it up. At no point during testing did the NVMe - I ordered the full Max kit, so I’m using the bundled one - reach anywhere near its throttle point either, so I’d say you’re good to go.
The possible exceptions: if you’re running the CPU and the NVMe at 100 per cent load for hours at a time, things might get toasty. Likewise, I’d have to revisit my testing as and when a more powerful SOM comes out. But for now, I’d say it’s not something you should have to worry about.