BMS lead load capacity and 24V System design check

[Starry-Nights]

Like many, I spent hours watching Will’s videos and working out the design of my solar system; changed wiring and of components often. Although everything now seems to be working very well, I have never had anyone really knowledgeable check it over. Battery and most components are boxed under bed which seems to modulate temperature well, keeping it warmer in winter and cooler in summer.

• High amps through BMS Leads: The 6 AGW leads on the Daly 200 amp BMS seemed too small so Installed a 500 amp relay, but it quickly failed (ok, it was a cheap Amazon one) so now running without. Wire size calculators suggest this OK since the leads are so short. Tested by running both an induction cooktop and a space heater (about 2800 watts combined) for 10 minutes. The 6 AWG BMS leads did not even get warm. Theoretical capacity of the 200 amp BMS I think would be 4,800 watts @ 24v. Any concerns?
  
  
• Sterling BMS Cutoff: Although solar has been working so well I haven’t needed to use it, the Sterling 12v to 24V B to B (BB122470) has a provision to turn off if the BMS activated protection. I believe the trigger wire from the Sterling BMS-1 terminal should be connected to the BMS P- lead. Anyone used this provision on a Sterling B to B?
  
  
• Omit use of MPPT Load terminal: Haven't done this, but one solar guru suggests it is much better and more efficient to hook DC loads directly to the battery and not use the Charge Controller’s load terminal. Seems I’d lose info of load on the MT 50 MPPT LCD, but I’d still have it on the AiLi current meter, as everything goes through the shunt. If more efficient, I'm interested. Comments?
  
  
• Battery Low-Temp solution: I live in NH and left everything connected last winter with the van parked outside. A tiny RV 7 watt elbow heater under the battery seemed to do a good job and my thermostat only cut off solar charging a few times when outside temps dropped below 10 F. Heater current draw was negligible and I left it on 24/7 all winter.
  
  
• One glaring omission: there is no master cutoff switch! Intend to install on positive battery terminal this week.

Any comments, corrections or questions on any of the above welcomed!

Tom