I might suggest always mixing the Ace with whatever you are using. Make sure it is mixed up in the syringe as well. You don't want it to sit at the top or the bottom. This will actually dilute the Ace.
I used to get bad coughing bouts until I started doing this. It's better to pin ED as well so the volume is down. It doesn't matter if whatever else you have are long esters or not. Divide em up and mix.
If you don't use enough of something else to make a difference by mixing them every day, mix on most days and give those ventros a try on the others. Shoulders have been good to me as well.
There is more than one spot on the ventros.
Injecting into scar tissue used to make it worse.
Until you feel comfortable, you can push the plunger down a little and wait a few seconds to see what happens.
I thought I was going down one day and even threw the pin across the room in case I passed out.
HDH