I remember reading many years ago that all the active ingredients are absorbed in milliseconds so all holding it in does is allow the smoke to cool and the heavier parts of the smoke like tars, waxes etc to clump together and stay in your lungs rather than be expelled on the exhale.
I haven't smoked joints in ages. Just small hits in a pipe to titrate my doses and even those have gone down to 2 or 3 late in the evening. I was using edibles a lot for my arthritis pain and growing high CBD strains for that. Since focusing more on supplements like salmon oil, MSM/Glucosamine, hemp seed, Omega 3s etc to reduce inflammation I'm not even doing that any more. I spend a bunch of money on all these supplements for that, dealing with prostate/bladder issues and health in general. I could get all sorts of pharmaceuticals prescribed and paid for by my medical but they all come with a host of side effects I don't get by self medicating.
Not sure about the vaping thing. Inhaling vapours of what is basically anti-freeze and other substances doesn't sound like a good idea to me but I plan on using an e-cig I have to help me get off the evil weed, tobacco. I beat the worst of a 40+ year run of chronic depression/PTSD and alcoholism by micro-dosing magic mushrooms over 3 years ago now so it's my last bad habit/addiction that I need to deal with. My right lung has collapsed twice now and that's no fun and can be attributed to mild COPD from over 50 years of smoking both tobacco and large amounts of pot/hash/oils back in my stoner days. I recently started using prescribed dextroamphetamine to deal with the ADHD that has plagued me all my life and it's the only pharma drug I'm currently using. An occasional aspirin for spikes in joint pain is the only OTC drug I use and that's only once or twice a month.
I'm still a big proponent of cannabis use for many things that ail us but thru personal experience and knowing many who overuse feel that chronic use indicates there are underlying issues both physical and mental that in many cases is covered up by it's use. Digging out the roots of these conditions has lead me to countless hours of research in the last 20 odd years that has me on what I think is a healing path for me. Sure wish I'd had the resources, and may I call it wisdom, to start this journey when I was much younger.
I'm still a bit of a mess but in a lot better head space than I can recall being since I was a child and still free of all the crappy concerns that creep into our lives as we age out of innocence. May your path be smoother.