Hi dad needing help and welcome to the site!
Beleive it or not, you have it easy... you should see what some other moms/dads are into here LOL...
To answer your question, our philosophy in the site does not encourage any method of controlled crying/crying out for babies or toddlers. As Tracey used to say, there's always a gentler solution to every problem, we just have to find it.
Although it might look as your son is soothing sooner by leaving him figure things out on his own, it might backfire you later or he might develop a clingy/needy behaviour as a result of this. He's not learning the lesson you think (I might better go to sleep now), but a different one: it doesn't matter how hard or for how long i cry, dad/mom are not gonna come to me. And that lesson might cause him further behaviour issues, as strong separation anxiety, nightmares, etc.
I'm not saying this to scare you but i'd rather suggest you to keep on trying the walk in/walk out approach you were trying in the past, even when you mention it took longer to calm him, he was getting the right message (it's bedtime but dad is here for me to help me soothe). It should be easier as time goes by if you remain consistant to one method and not give in. The walk in/out technique is thoroughly described in the FAQ section of this forum, under a thread named "teaching independent sleep".
You can also talk to your son during daytime/bedtime routine about what a big boy he is and how great it is that he can go to sleep on his own, dad needs his sleep too, etc. They understand so much more than we can say at this age. Introducing a lovey (blanket, teddy bear) for him to hold might also be helpful to soothe him and think he's not alone.
I hope you find this info useful and please keep us posted about your progress. Good luck!