rim band and joists space ?s

Hello ,good morning got some ?s about truss spacing ,I was going 4ft oc but could go 2ft oc for 600 more bucks is it worth it stronger?,no purlins?wdyguys think? and one more ?on my rim band Iwas going to notch 6x6s and put 2-2x12 together on post curios about if i notched each side of 6x6 for 1 2x12 is one better or stronger than the other? I was thinking about that sandwich because you could put truss supports in between,thanks again for the responses and feedback PRESS ON, BUILD ON !

Out here on the left coast we usually put our trusses on 24" centers. Just seems to frame easier w/o the need for purlins because we use roof sheathing of ample strength. Also, I used a ridge board to give support, which the roofers appreciated.
Sorry, but I don't understand the second half of your question, but I'll make a guess. I'm wondering if you are talking about the blocking required between the truss end rafter tails. We used 2x material to fill the gaps and stuccoed the underside of the overhand along with the walls. We living in a fire zone makes this a good idea.

thanks for response curiosity was about either putting two 2x12s together for rim band notched in or putting a 2x12 on each side of 6x6 notched in. Is there any difference in strength or building ?or does make a difference?hope im clear enough?