No worry about the medicine entering the blood too quickly. Both of you will inject into fat and absorption will be gradual. I usually add a bit more BAC so the numbers on the syringe are easier to read accurately. Twenty units is simpler to measure than ten. I print a small chart that lists units for each dose and tape it inside my kit lid.
Is it safe to mix the 60 mg vial with just 1 ml so that 10 units equal 6 mg? That matches my wife's dose and would keep things simple. I'm worried an extra unit or two could deliver too much or that the concentrated solution might not spread well and cause nausea. I'll switch to this vial once my current one is gone so fridge time isn't an issue. We use 8 mg and 6 mg so a bottle would last under five weeks either way. Would 3 ml be better so 30 units give 6 mg and 40 units give 8 mg? BAC water is cheap and I have U-100 syringes.