Mario, I'll give you one additional thing to consider. Your question asks about what is possible, but another variable has to do with preferences.
Like has already been stated, it is possible to do the ocho cortado without opening up the embrace (your preference). It is also possible to do it while opening up the embrace (her preference).
Both ways are possible, but you have different preferences. If you accept that, then it comes down to how do you (the leader) decide what you are going to do, when you are dancing with someone who has a different preference from you.
The options that I can think of (right now) are:
- Accomodate her wishes.
- Maybe compromise somewhat.
- Lead so that she has no choice but to do exactly what you want.
- Just end it and say Thank You.
The only problem that I run into, is that my first assumption (when something doesn't go as expected), is that my lead wasn't clear enough. It sometimes takes me a little time to figure out, that she simply doesn't want to do it exactly like I am leading it. Once I do figure that out, then I'll try either the first or second options that I listed.
After the tanda, you can decide if (and when) you want to dance with her again.
One thing I try to focus more on is what I can do well with any given follower, rather than just what we don't do so well. No offense intended, but your strategy would seem to greatly limit who you will be dancing with. While that might seem OK right now, your preferences might change a bit, down the road.