I’m interesed to make my first blend with MMB-CHMINACA and i want to use 1g for 20g of diamana and i know to use 5ml acetone, For a start your ratio is too high. I am a very heavy smoker of mdmb-Chminaca and my blend is 40 to 1. I also use isopropyl alcohol and i would use at least 200 ml to make up that blend using the bathing method. Better having too much liquid so as everything is drenched and to keep stirring. It may take longer to evaporate but i feel it is safer and less chances of hotspots.
The Cannabinoid may well dissolve in 5ml Acetone but I’m not sure if it will cover 20g of damiana fully. There’s no harm in using more if you need it though it will just take longer to evaporate (this can be sped up by using good ventilation and an electric heatplate at ~30C)
Remember to keep stirring the mixture to get as even a spread, and when it looks all done and dry leave the plant matter for at least another day, just in case. Don’t want any remnants of the solvent left in there, especially when lighting it. And i’m sure you know, but dissolve the cannabinoid in the solvent before it’s added to any plant matter.
Also not sure where you got it (and not going to ask) but MMB-CHMINACA is an incorrect name, correct naming would be MDMB-CHMICA.
edit; spraying is highly inaccurate and prone to hotspots ,
Best practise for equal distribution is to submerge the plant matter in the noid-solvent mixture in a glass/beaker and keep it on stir until enough solvent has evaporated so that it cannot anymore, if you don’t have a magstirrer then just stirring with something non-reactive every so often is usually good enough. then lay it out to dry on a glass plate or some flat aluminium foil until fully dry, just resist temptation to scrape any crystal/powder off the sides of the glass though until the plant matter is out, you can do that later and if you have good enough scales gauge the actual adjusted mg per gram of plant matter.
It is worth using gloves or avoiding touching the mixture with your hand whilst it’s wet too, just to minimize any accidental consumption
Also spraying 50ml will take a while