"Ncore is a very good amplifier with most of "usual" speakers"
In theory is yes, but practically we do need to measure the capacitance that is present at the speaker banana plugs.
We may have some surprise depending how the crossover is designed and what is the drivers size.
I remember measuring 4.7uF with a 5.25" midrange (not connected to the crossover) using a LCR meter.
I need to make new measurements at the speaker banana plugs level.
More worrying is the Pspice model of a 12S30 BMS speaker (12" subwoofer).
https://circuitdigest.com/electronic-circuits/simulate-speaker-with-equivalent-rlc-circuit
The larger capacitance is 240uF.
When playing music, if there is no bi-amp, the class D amplifier will have to drive the large woofer capacitance and in the same time drive the tweeter without any distortion.
After the very useful measurements made by
@pma I do not feel well driving a large tower speaker without a class D Bi-amp.
Distortion in the high frequencies will be an issue.