Extended Primary Temperatures?

[cottlad]

I'm about to start my first ever kit. Muntons Gold Stout. Instructions say transfer to bottles/barrel after primary fermentation (about a week at 21ish degrees.)
I have read in a few places that either secondary fermentation or extended primary will give better/clearer results. If any, I'd probably go for the extended primary (maybe 2-3 weeks) and I was thinking that the 2nd & 3rd weeks I could add some flavours (want to try coconut.)

Is this a viable plan, and if so, what temperature should the extended primary be at? Keep for duration at 21' or allow to cool?

Instructions call for 2 days at 21' once bottled/barrelled but if I extend the primary, would these instructions change?

I'm thinking I should keep it at 21' for the full 2-3 weeks, then barrel with sugar, keep at 21' for another 2 days, then allow to cool and finish clearing? AMIRITE?

Sorry for the abundance of questions.... Just want to get my first brew right :)

 

[MyQul]

If your able to easily keep it at 21C for whole time in the primary great. If it's a bit of a faff (such as using ice bath like i do which requires a bit of monitoring) just keep it at 21C till it's finished fermenting then you can just leave it for the yeast to clean itself up.

Once bottled (not sure about barrels as i've never used em) , standard is 2 weeks in warm to carb up then 1 week in cool to force CO2 back into beer

 

[cottlad]

I'm building a heated fridge for fermentation so should stay at 21' without any faffing hopefully.
So I'll keep it at 21' for 2-3 weeks but add a bag containing a pound or 2 of unsweetened roasted coconut flakes after primary fermentation. Then after week 3 i'll remove the bag and transfer to a barrel with priming sugar, 2 more days at 21' in the barrel, followed by more time at a cool temp to finish. I know I'm waffling here, sorry :) Does this sound about right?