I would try holding your tongue as far back as you can for many months without any snipping. This will increase your bhakti and make the tongue ready to go up. This would only work for you if it is appropriate, it may or may not bring you closer to your goal, stage 3.
The tongue has to stretch in order to reach the third eye, and if you snip too much then you could end up compensating for a lack of stretching. The best way I know of to stretch is to allow conductivity to pull the tongue upward. You could actually over snip and because the tongue is not properly stretched or strengthened, you will not reach third eye. These are just possibilities to be entertained, words on the screen that mean little.
In my experience, the tongue would be pulled up and held in place almost like a magnet. Then chi would flow through the region along with the rest of the body. This caused the tongue to fatten and stiffen upward. Slowly it would creep up, applying great strain on my frenum. Many times the frenum would feel like it was about to snap but did not, it just stretched. Just a few times it actually clenched my jaw shut very tightly. When I pulled the tongue down the frenum was white and had many curls in it from stretching. Then it would dry a bit, heal, and be longer than it was before. Slowly, but SURELY, stage 3 was established.
I practiced stage 3 for a while but then moved on to other aspects of my body that need attention, even though I practice stage 2 every day with the same effect or more. A long time went by without practicing in stage 3, but when trying to clean my tongue I pulled on it and saw a bit of blood on my hand and lip. My frenum had torn slightly from milking my tongue, which was accidental.
I think if I wanted to I could milk the tongue, practice stage 3, and make it even longer but there is no compulsion to do this as of now. But there have been a few occasions where I was overcome by kundalini and went into stage 3. It felt like my tongue had merged with my brain, in respect to how the ecstatic kundalini flowed.