Calculate temperature for low side switches?
The junction temp rise depends on a product of switch resistance, Ron times the total thermal resistance to the internal ambient where using a heat spreader of copper substrate or a clamped case heatsink can greatly reduce the case to ambient resistance but is bulky unless forced moving air velocity is high.
Assumptions and variables for each driver must be combined to determine the total power loss and heat rise.
Choices and calculations:  for temp. of jcn (Tj), case (Tc), ambient (Ta), and interface thermal resistance between each, Rjc, Rca where Rca depends on air flow and if a heatsink is used otherwise none, just convection open air Rja.

Heat loss: \$P_d= I^2* R_{on @ T_{j ~max}}~*~N_{drivers}\$

Temp. Rise = \$P_d*R_{ja}\$ unless a heatsink is used,

then Rja=Rjc+Rca.


Absolute max energy clamp diode = \$E=1/2 ~LI^2\$.

Max Tj=85’C to 100’C depends on reliability not worst case, Ta (inside) , case design.

cost and size may be critical factors for getting lower Ron FET’s


Simulation example of transistor switch driven from an ESP at 3.3V using Ic/Ib=20
Lower Rce = Vce(sat)/Ic