I have added the boards to Tindie for anyone who wants them. The design is generic to any of the MAX3010x series modules, so we will sell all versions. The design we made is pretty minimal compared to Sparkfun's MAX30105 and others. The MAX3010x series is 6V pin tolerant, so much of the i2c bus wrangling is unnecessary.

I am also looking at using something like the TPS8268180, though it is a little pricey it may be easier to build with by hand compared to the LM3671TL series BGA.

The photos aren't great, I will have a new camera and light box configuration soon:

https://www.tindie.com/products/Fyberlabs/pulse-flex-module/