This will for sure make an awesome 2nd build! Lots of premium parts here. Flipsky battle hardened 6374s are some of the best bang for your buck these days - doubt you will find much better.
If I may suggest an alternative on the battery holders - look into NESE battery modules:
- https://www.youtube.com/watch?v=9OPqMC_y9pk&ab_channel=agniusMikutavicius
- https://www.youtube.com/watch?v=93JBo87LJiU&ab_channel=agniusMikutavicius
- NESE, the no solder 18650 battery system
- [Serious] Post your NESE builds showing the pack and mounting style
- https://18650.lt/index.php/product-category/nese-21700/
- Free STL file NESE, THE NO SOLDER 21700 MODULE V2 (VENTED) 🔋 ・Design to download and 3D print・Cults
Similar to your first build modules, but have undergone a good bit more testing and development. Good experience on the forum as well.