From archived links:
This is washer in question, SQ model #CTS90awn
http://www.plessers.com/Speed_Queen/cts90awn.htm
These came with or without "boosted hot" IIRC, but don't know if model numbers changed if heater was added.
If you read the above archives you find the machines had various shortcomings. So in the end Alliance likely figured best to ditch the heater option rather than spend money on R&D to make it work with their washers.
Keep in mind at least in early days SQ domestic front loaders were really nothing more than commercial machines with a different outside package. In some respects that is/was a good thing (rock hard build quality for instance), others not so much.
On the domestic commercial/laundromat side SQ H-axis washers have connections for steam that heat water. Do not think any offerings use electricity because the market would be small due to cost of use.
Case in point; my AEG Oko-Lavamat will heat tap cold water up to near boiling (95C) in ten minutes or less. This using a heater rated for at or a bit over 2kW.
OTOH the SQ with "boosted heating" would likely have taken ages to heat tap cold water to 140F with a puny heater and 120v. Hence the cycle was called "boost", idea likely was that like a dishwasher machine only raised temperature of already hot tap water, to 140F.
However if the pre-wash was done in cold water (which can vary in temp by time of year and geographical location), the wash is going to be quite chilly, that will in turn lower the overall "hot" tap water. More so if the washer didn't or doesn't spin some of that pre-wash water but merely drains it away instead.