Calculation Include Tax Option

Just quick one to note the include tax option on calculations wording could be clearer.
To me i would have expected include tax would be to set is tax amount would be included in the calculation amount however it seems to relate to the inverse as to wether or not the calculation value is taxed.
With including tax pricing and include tax unticked tax is calculated including the calculation amount. So ticking it then means the calculation is made on subtotal after tax is calculated.
Im less familier with setup where pricing is exc tax and havn’t played my with that option in samba but description doesnt seem correct to me.
I beleve the use plain sum option relates to using ticket total or subtotal however this doesnt seem to make a difference for price including tax setup meaning price including tax setup cannot do calculation based on net of tax total without custom setup or presumeable a factor in why some then switch to using calculations for tax rather than tax templates.