MG Sandrock clean build. Going for desert vibes. Thoughts?

This is my first fully painted kit, top to bottom. Some things I learned - don't get plastic parts too close to your space heater - at the risk of sounding like Megatron, PRIIIIIIIMMMMMEEEE. - Clear coating before matte coat to apply decals and paint detail doesn't make the parts impervious to chipping or any other nefarious scratches if you're not careful

Is it acceptable to paint the inner frame only where joints/ exposed bits are? This took a hell of a lot of paint (especially that dark brown, wiped out 70% of my tamiya jar).

Thanks for the advice in advance!