I have seen previous posts suggesting that use of the new class E procedures was forbidden by various company ops manuals, however you may be affected by a VFR climb/descent or IFR pick up anyway as only the aircraft using the procedure needs to think its a good idea (VFR on top probably wont bother you as I cant see any sane pilot requesting it).
In LLAMP both aircraft had to agree.
If, whilst in E, you are issued traffic on another IFR aircraft that doesnt think he/she needs separating from you and you would prefer to maintain the integrity of your clearance, voice your concerns to ATC. I for one will do whatever I can to ensure that those aircraft who want to be separated are separated.
I do think that under the right circumstances pilot assumption of responsibility for separation is an excellent tool, however both parties should have a say.