Seems there are 2 ways to start my truck.

First way is to use the GP's and start cranking after the WTS light goes out. I'll usually see 2-3 more cycles after it's started. What dictates the cycles after start? Is this a stock feature?

Second one is to just start cranking, not even wait for GP's. Most of the time it starts normal when done this way, although I usually dont do it this way. Especially not for first starts of the day. But I notice that if I do it this way, there is no after start GP cycling. Why?

I know it's always best to use the GP's, but after it's warm, it's sometimes nice to just turn and go. Anything wrong with starting this way?

The cycles after it starts it normal, the computer just wants to protect the engine from the cylinders being washed down with raw fuel. You want to do the same - prevent the cyls from being washed down.
The glow cycle is shorter when the engine is up to temp. There's a sensor that tells the computer how hot the engine is. If you still have somewhere about 10 seconds of WTS when the engine is hot, that sensor may be bad.
OTOH - Count up the seconds you save not waiting on the glows. If it takes you fewer seconds to rebuild the engine you've come out ahead. Maybe this is where the *Time Is Money* saying comes from?

Seems there are 2 ways to start my truck.

First way is to use the GP's and start cranking after the WTS light goes out. I'll usually see 2-3 more cycles after it's started. What dictates the cycles after start? Is this a stock feature?

Second one is to just start cranking, not even wait for GP's. Most of the time it starts normal when done this way, although I usually dont do it this way. Especially not for first starts of the day. But I notice that if I do it this way, there is no after start GP cycling. Why?

I know it's always best to use the GP's, but after it's warm, it's sometimes nice to just turn and go. Anything wrong with starting this way?

1. Yes should be like that up to 15 to 16 seconds total.
2. IIRC, the Coolant Temp Sensor is the one that give the signal.
3. Make sure you use the GP, I read here that it may ruin your engine if you do it everytime. Cylinder don't fire properly if GP is not hot.

I notice you live in Canada, may want to check your GP system before the winter. Although, you are not in the coldest part of Canada.