MT, sparring, aliveness

I train MT, and I love the aliveness ideas of SBG, which I interpret as getting things to work against a resisting opponent.

But I'm interested in the contact level that is appropriate for sparring in MT. Does sparring at a moderate contact level (say 30% power) negate the aliveness idea? Does it need to be full contact sparring sometimes? If so, how often? Or does the fact that you are working with a partner mean it is still valuable even if power is cut? Is there a danger of this leading to technique modification (witness the 'tag fighting' in some semi-contact competitions)

(Note I'm referring to a recreational trainer here, rather than someone getting ready for the ring)

There is no problem training standup alive with light to moderate contact. The top camps in Thailand train sparring this way to develop superior timing and mechanics. But this mode is much different than the "tag fighting style you mention).

Like everything else, contact levels can be built upon with progressive resistance. If you are interested in fighting, then you would need to ramp up the contact so that there are no surprises. Most of the training, however, will be more controlled contact.