I have to be perfectly honest, firstly I have only ever once re torqued a head and it was not necessary anyway (always alloy heads for me) I have never blwon a head gasket in my life, always solid copper ones.
As for the rocker box, I dont release the tappets altho I do release the locknuts, I dont use a comb and I dont use elastic bands. I could literally take it on and off in my sleep I think I have done it that many times in 45 years.
Plonk it on, find which ones you have located instantly, normally 3 for me, hold the box by those 3 rockers keeping them tensed on the push rods, wiggle the last one in place and its job done.
10 to 15 minutes and that includes putting the 4 long bolts in and pulling them down.
Maybe I just have extremely long fingers or something