NHRA / CMRA , and for work NEC / NFPA / OSHA / IBC plus an AHJ of whatever city / county
Awesome. Now forget all of that because it doesn't apply to this venue. No one is getting paid to work tech, or trying to fail people. No one makes any money if you fail or if you pass. The riders going thru tech are doing so to ensure a level of uniformity and safety for them and for the others around them. (30 years of OSHA work in machine shops here, btw. And Solo I & II D Mod))
This is the mentality for the IBR technical inspections: The inspectors are there to help you. We are going by the rules and will fail you if you do not meet them, but we will also tell you what to do to pass if you have an issue. We have a lot of combined experience. I've set up multiple bikes for aux tanks and am a machinist and fabricator among other skill sets. Others bring even more experience and different skill sets to the table.
If you fail, you have time to correct the problem(s) and come back to re-do tech. Tech goes on over three days. Most riders finish it on the first day, some choose to do it on the second day, problem people may still be sorting things out on the third day. You are encouraged to deal with the problems and come back because you paid to be there and we want you to ride the IBR.
There are issues that require second level discussions, like any venue. The white plastic tank on the 300X was designed specifically for that application on motorcycles and feeds via a vent line. It's nothing new in performance and as long as it's well mounted, vented and follows the other rules, it's fine.
The main things that get failed are simple issues;
Poor routing of a vent line where it isn't to the back of the bike or dumping away from the rear tire.
Aux tanks that don't pass the 'shake test' for mounting stability.
Vented caps on aux tanks.
No ground wire on plastic tanks or metal tanks that are not grounded via mounting points.
after that we see on rare occasions things like:
fuel hose routed too close to heat areas.
over volume aux tanks.
aux tanks mounted to seat pans (not allowed unless the seat pan is bolted to the bike).
No baffles or foam in larger aux tanks.
If you're building your own cell or having one custom made, put baffles in it, take pictures during the construction to show this. If you're making a complex shape tank that will be difficult if not impossible to physically measure with a tape when it's installed on the bike, do the math for it's volume, print that on a sheet of paper to show the inspector, but you may end up having the tank measured for volume as well. That takes time and is a minor hassle for both the rider and tech staff. Better, arrange well ahead of the IBR to have your tank measured for volume by a IBA technical staff member, usually the head of Tech or a staff member he designates to do this. Depending on location that can be a simple as a meet up in person, or could mean shipping your aux tank to them to be tested. Waiting until the IBR is certainly possible, but most people have over a year after they know their application has been accepted, so there really isn't much excuse for not getting it done ahead of time.
So again, what are you trying to do and what's the problem? What bike, design style, (flat bed, tail dragger, pillion seat, cube, cylinder, complex shape), location on the bike and what features or issues you are concerned with?