Sounds like a frustrating issue for you....but a delicate & uncomfortable topic for Masters you may have met?
While every bdsm encounter can deliver a range of mutually beneficial exciting arousing excitment, I cannot imagine any bdsm relationship blossoming or progresssing into anything that can last -without a clearly communicated discussion of: Prefs & Limits.
Of course this list will evolve & grow!!...(isn't THAT one of the biggest expectations of the anticipation for the relationship..!?)...but AFAIC this MUST be discussed; if for no other reason than to abide by SSC.
In traditional "dating" or even referencing back to the times of 'courting', one of the intents of "spending more time with", was to find out among other things, what he/she likes or does not, enjoys or detests, reacts to or does not etc etc...
Now, I can think of more than a few humerous retorts to add to this point, but one of the advantages of seeking out a bdsm relationship is that much if this process can easily be fastracked with a simple discussion of: What are your Preferences & Limits!?
[NB - this does NOT negate or exclude the need for 'dating' & moving slowly and getting to know your partner EVEN in a bdsm hook-up!!]
Thus if you can capitulate what you seek, what you crave, where you want to 'venture, AND your Limits, I am confident you will have better luck finding a Master who will be more comfortable and better equipped to deliver you to the extreme exile you dream of, AND maintaining a Special level of Trust that you will also need to be reassured of.
Switchablesuzie's point is a PERFECT example of this, and I wonder if in previous attempts, if you weren't able to establish this Pref *AND* Limit as clearly as she did; it may be the reason why others were unclear how "far" to go.
Hope that is helpful...?