This seems to be proceeding back-asswards. The roots have some capacity to grow the top, in proportion to the size of the roots. The smaller the top is in proportion to the roots, the more that growth is going to be expressed as water-sprouts. That just aggravates the natural tendency of this species to have long internodes, giving you the worst of both worlds. You are growing a potato with telephone poles. I don't think that's what you're after...
The only way to divert growth into shorter internodes/earlier & more ramification is to pinch the leader, early in the process, before it grows that long internode. That's a double-edged sword here, too. It will respond by putting out clusters of buds, like 10 or 20 in a cluster. All of these responses are perfectly normal because the roots are grossly out of proportion to the top.
A better strategy would be to lift it and put it in a ~large-ish (bigger than typical) pot to reduce the imbalance of roots-to-top. Pinch the leader every time and place where the internode reaches the length you want. You will still have too many twigs/branches sticking out all over the place, but hopefully some will be located well and others will be sacrifice branches. NOT sacrifice branches in the ordinary use of growing part of the trunk, but in this case useful to use up surplus root energy, so some sacrifice branches can be telephone poles as long as they are well-placed, AKA not sticking out of the front or where the scar will be counter-productive. After the basic architecture is set you can sink the pot and get some more vigorous growth, but you will still need to short-cut long internodes by pinching leaders. The species has long internodes and will forever want to revert to type.