Laser hair removal questions

Ok, I had my first laser treatment on my chest and abs. I am a 22 y/o white male with dark hair. The laser that was used was an alexandrite and the energy used was 17.5 joules. My chest and abs are pretty hairy.

I noticed after the treatment that the hairs did not grow back, although this only lasted about 3 weeks. I didnt notice many hairs fall out. Now the hairs are growing back in and my second treatment is coming up.

I asked them about the energy that was used, since it seemed a bit low. They said that they like to increase each treatment(my second treatment will be 20 joules). I asked them, if they increase the energy to 25 or more joules what would happen. They said I would likely blister and possibly burn (I am an average white guy, type II or III skin). Does this seem right? Are they being a bit too conservative? Will I get results this way? They said by the time I have my 5th treatment I will be hair free.

I am getting a really good deal compared to the prices I’ve seen other people say they pay, but I dont want to be throwing away money either.

What should I do?

Personally, I think it’s better to err on the side of caution to avoid blisters, etc. Maybe they can do a test to see how you do with higher fluences. The key with multimple treatments is communication. If they have made some sort of guarantee of results after a certain number of treatments, get it in writing if possible.