Setup

I 3D-printed one of these cases to use with a XIAO nRF52 / SX1262 Meshtastic node.

https://www.printables.com/model/1346041-meshtastic-seeed-studio-xiao-nrf52-sx1262-case

However, the 18650 3.2V Li-ion attery I have is unprotected and I want to be safe, so I bought battery protection boards:

10pcs 1S 3.7V 3A li-ion BMS PCM battery protection board pcm for 18650 lithium ion li battery https://a.aliexpress.com/_mr9W3lj

I soldered the battery contact pieces to the B- and B+ of the battery protection board. Then I soldered the P+ and P- to the BAT + and - on the Xiao NRF52840. This video mostly sums it up.

Question

I know this may be pedantic, but I know my limits and would rather get things right. Before I put the battery in, I want to confirm:

1. Is this design safe?
2. Are there ways I should test the design first?
3. I used whatever cable I had laying around, but is there an ideal gauge to use from Battery->Xiao and from Battery->BMS?
4. Are there recommended ways to improve this design such as a fuse?

I need a small solar charge controller for a 4.2V battery and a 5V solar panel. In my research, I found the SD05CRMA and the SDBK03TA 4V2.

Both use a 472 and a 1201 resistor. They both also use a CN3163 mppt lithium ion battery charge controller.

I see no other differences besides price.

Are there any benefits of one over the other in terms of physical architecture?

I was reading the changelog for the Home Assistant SLZB Add-on and saw they added support for the SLZB Ultima. I looked it up on Aliexpress out of curiosity, expecting it to be their most expensive offering since it has 4 antennas for Z-Wave, Zigbee, Thread, and 4G/LTE. Also RGB (eyeroll). But its price is similar to other SLZB offerings. I'm suspicious since it seems too good to be true. Is the price low because there was no support previously or are there problems with the device?

If you are more tech savvy, you can use Nextcloud.