My wife's friend has an 18 JK but found out there are some JL features installed too. Her JK has the auxiliary start battery that the JL came with. She was having starting issues. The dealer installed a new battery, programmed new fobs, flashed the security, and it still had the same problem...
Welcome to the forum! Get rid of those junk terminals. Wiggling the blue fusible link alternator wire might of wiggled that terminal enough to start it. I had no start issues. Thought the terminals were tight because all the nuts were tight but the terminals weren't tight enough to the battery...
Did you scan it and see what code(s) are stored for the HVAC? The light blinking can mean a few things like blower motor resistor is bad/corroded, rear defrost relay/fuse is bad, actuator(s) need calibration, or the HVAC unit itself is bad.
https://motobilt.com/products/off-road-jack-mount?srsltid=AfmBOopQu4O2YOpCGnEdpLZEBQKH0J3n1LCV8oGKzFw6LHbWH1l75aRu
Pricey but mounting looks universal. So maybe the rollbar is an option?