RE: Figure 8
The thing is the illustrations by Rokuhan are sometimes more artists renditions, not 100% accurate track plans. It’s explained by Rokuhan themselves as well as the author of the track planning software, Anyrail, in these two articles:
In the second article I was sent a sketch directly from Rokuhan illustrating this, as well as the comment:
"We selected, by chance, to develop 25mm and 55mm straight track. If you ask for real “accuracy” on Z scale, really PRECISE dimensions would be necessary, such as 18.678mm (just as an example). However, we think pieces like this would be impractical in the current Z scale world."
Also you can see the PDF (link below) of the 90 degree crossing where Rokuhan lays out the track pieces needed for different Figure-8 patterns but realize these Figure-8 patterns are illustrations, not accurate track plans, there will be gaps using these patterns according to Rokuhan.
The gaps you’ll see sometimes are very small and as Rokuhan says, there’s enough wiggle room there so you can put together many plans with no adverse running effects.
If you want dead-on perfect fitting track, you can always cut and tweak track but in running several Figure-8 patterns with trains from MTL and AZL, I've seen no negative results from using small amounts of wiggle room to make them fit.