GMMK Compact thoughts/alternatives.

There aren't many DIY keyboard parts/shops in my european country (at least I couldn't find one), but I found GMMK keyboard in a local (mostly online tho) shop. Is it a good pick? Will it allow me to freely rebuild it with other parts (even pcb)? How is it with software and features? Does it lack any featuers I may not know I may need (I never have used so small keyboard, my current one is TKL)?