Cascade maple nebari development

I obtained a seed grown cascade maple. Still in the nursery container,
I have three surface roots showing. Should I repot into a shallow wood
box to develop more surface presentation or should I work on the branching
and repot into a taller pot?

My direction would be to work on the root structure first to ensure a basic structure for the tree!
Begin removing downward tap roots and balancing surface roots for a more even nebari. Also I would consider the cascade branch as a possible sacrifice to thicken the trunk. Using the lower branch as a new apex to develop taper and change of direction over time.
I must admit that my bias is to avoid cascade as a style for trident maples. I prefer to work with their natural growth characteristics and style branches in an upright fashion.

I agree with Frank re: using the horizontal branch as a sacrifice. You could make a semi-cascade with that branch, but the lack of an acute downward angle would make for an awkward cascade. Using it as a sacrifice will introduce nice trunk movement.

I appreciate the feedback. I want to work on surface root development also.
Using the shallow wooden box technique, I have two problems. First, the
main descending branch lies far below a 3" wood box, so I can place this entire
box on a table. The second issue is this: Should I use just the shallow box for
restricting downward root growth, or, should I place a tile under the root ball for
additional upward re-direction of the roots toward surface presentation?

The base of the box will provide the same redirection as a tile. You can place the box on another box or any object that will raise it sufficiently above the table or bench. Your good to go!
Have fun.

thinking about getting myself a cascade maple. never had any so all your recommendations really seem to be helpful for me. working as a cooker working with various recipes and ingredrients, i was thinking to place it in my kitchen. does it sounds like a good idea?

@Carld1 - it’ll be tough to keep a maple healthy indoors. In general, they do much better when grown outside.

I agree. Morning sun depending on your locale. Mid day to evening shade. They need protection when the temp goes down toward freezing.

that’s the reason why i thought about kitchen - gonna check them while doing my recipes. i heard about them being fragile, and i do know that they are better known outside, is just the fact that i’m fearing about the cold temperatures as well as other external factors.

Maples REQUIRE sun. They also need to go thru a dormant period induced
by cold temps. Consider a cold frame or other such protection for the root ball,
of a cascade maple.

FYI, Michael Hagedorn has a really interesting discussion about dormancy requirements in his forthcoming book, Bonsai Heresy. I highly recommend it!