You're over-thinking things....
Unless you are pulling mega-watts of power, load balance on the utilities transmission lines is not your concern. If you have 3-phase power you only have to reasonably balance power from your distribution panel. If you have single-phase power it is still the utilities concern - not yours. Of course this also assumes that you are in a fairly well developed country with stable & modern power grids.
In most countries 3-phase is typically delivered to a building as a wye connection with a center Neutral connection - not delta. However, that also depends on the local power loads. Wild leg or high leg grounded delta is usually only found where most area loads are single phase and only a few select customers need 3-phase. Unless it is your only choice, due to the voltage imbalance between the wild leg and Neutral I do not recommend grounded delta.
What country is this in? How power is distributed varies between countries and even between regions within a country.
What voltage is your typical wall outlet at home or business? 110v or 220v?
ref
https://en.wikipedia.org/wiki/Three-phase_electric_powerIf you want 208-240v 3-phase power, and if the location also needs a lower voltage for wall plugs & lighting just tell the utility that. They will decide on the type of transformer used as it all depends on how they distribute power in the area where you are.
I'm in the US. Do miners such as antminers run more efficiently on higher voltage? (this is why I was aiming for 240v) as well as the increased effiency gain from higher voltage (less current).
For larger setups I keep seeing that a 415/240 volt transformer is ideal, so I figured 240 delta was similar.
Anyways seems like I should avoid the grounded delta though because it is an unusual setup.