I'm not a sleep researcher, so I'm not really qualified to say. I did poke around and find some papers on caffeine's affects on sleep, but there honestly wasn't

I'm not a sleep researcher, so I'm not really qualified to say. I did poke around and find some papers on caffeine's affects on sleep, but there honestly wasn't (IMO) a huge amount a research, and what I did find mostly focused on caffeine intake less than 6 or 8 hours before sleep. Everything I found did see differences in brain activity or REM, but there seems to be room for interpretation on what those differences actually mean (turns out brains are really complicated). I did find this though: "Regular Caffeine Intake Delays REM Sleep Promotion and Attenuates Sleep Quality in Healthy Men" >Our data indicate that besides acute intake, also regular daytime caffeine intake affects REM sleep regulation in men, such that it delays circadian REM sleep promotion when compared with placebo. https://pubmed.ncbi.nlm.nih.gov/34024173/ https://pubmed.ncbi.nlm.nih.gov/34024173/ Based purely off of my layman's intuition, changing how you sleep is not optimal for brain health, it disrupts a natural and very important process.