Soft 404
Ah yes boot times. The gold standard will always be the Commodore 64. 
So it looks like your goal is to boot up and do some 'camera stuff' every 5 minutes. Makes me wonder, does your end application have anything to do with time lapse photography?
The C64 definitely beats my RPI . It took me a few minutes to find this video I remembered watching the author is comparing a tandy 1000Rl to a C64
https://www.youtube.com/watch?v=JIEPqD4luG8
I also tried baremetal circuit python on my RPI ZeroW, the boot time was pretty disappointing at 5.6 s
Really I just want to upgrade my IOT Birdhouse to V2.0
I definitely want to have a RPI ZeroX and a Pico inside, solar panels on the roof,... then the opportunities should be endless 
Now that reminds me to double-check which way round the bargeboards go on the gable ends of the new garden shed...
Learn from my mistakes! Connectors... 
they always end up backwards...
Learn from my mistakes! Connectors... they always end up backwards...
