Just started trying this deck out last night after researching it the past 2 days and I have to say I'm very grateful for the wonderfully well thought out and detailed op. I haven't played since last year Zoo nats format so getting used to the year's worth link era increase in cardpool has been the greatest challenge. I tried out all the ideas in the op toon engine, goods/fusion, diabolos and different ratios of theme cards and hand traps. I feel like there's a handful of good generic cards that can supplement the lack of aggression and game ending potential we're missing in the TCG without needlefiber, but for the most part I think pure Brandish is extremely viable if not the best variant due to versatility and ability to out grind the mirror especially if they dilute themselves with another engine. More than anything I'm glad to be playing again and am eager to engage in theory discussions with the members of this site once again.
There's a couple of things which experience actually playing the deck taught me were slightly off as presented in the op. I think it's actually not a bad idea to build the deck with the idea of getting 3 spells in grave asap since the marginal benefits rack up quickly especially with engage's draw, but in general the mirror gets significantly easier when you have more spells in grave than your opponent, thanks to red you can be more aggressive against all match-ups early on if you fill the grave. Noelle is right to warn against haphazardly building to get 3 spells but if the proper thought is given to achieve this goal less directly and as a consequence of improving the deck's consistency overall then pitfalls like limiting the deck's versatility can be avoided. I think the most egregious offender of blindly building to get 3 spells is the toon engine, not so much because of the potential to draw bad hands with multiple toons but mainly because nothing substantial is achieved with those 3-4 slots as cyber dragon is seldom impactful and can sometimes be awkward or useless and cannon soldier in enabling Diabolos is even more limited. This engine limits the deck's versatility to an intolerable degree imo for the little it accomplishes, its the type of thing that's popular on pojo because they can't see the big picture(the deck's goals and win conditions).
The best goals for deck building should simply involve improving access to rei, engage, and less crucially 3 spells in grave asap this ensures that you will outpace the opponent in the mirror with good technical play, if in the process versatility can be increased all the better, toon engine doesn't assist in seeing rei or engage turn 1. In my build I achieved all three goals by playing 3 Terraforming, 3 field spell, 3 mst, and 3 twin twister. Field spell+mst/twin twister+any theme spell results in floating rei, red->blue, that same spell in hand, 3 spells in grave or more depending on terraforming and twin twister, and potentially one more brandish card off reveal from field and you can play around cherries. Mst and Twin twister are vastly more versatile than toon engine and open up room in the side that would normally go to addressing IO and ASF games 2 and 3, as well as allowing plays to be made more easily against the mirror. As far as I can tell the only practical way to improve the chances of seeing engage is with field spell and foolish goods, goods engine with fusion is already extremely versatile at all points in the game. Another card I chose to play which was undersold in the op and that works really well with the extra s/t removal and field spells is Hercules Base which almost guarantees you win the grind against the mirror not just by allowing you to recycle your extra deck maidens but also by getting draws from beating over their links and cutting their rei off from floating or netting an extra draw.