New (to me) Lexus GX - White Smoke from Exhaust

[ttg7ya]

Gents:

Friday evening, bought a 2019 GX 460 with 87,000 miles.  Clean carfax.  One year lease followed by single owner.  Been wanting one for some time, but wanted the light color interior.  Passed on a Lexus certified 2018 that was not as well maintained (on the surface).  Shame on me.  

Interior spotless.  Frame and undercarriage immaculate.  

Maintenance records good but not perfect.  Not much logged last couple years.  

Paid 30,500.  

Three days and 40 miles later, was driving back from picking up fiance from airport and got pulled over.  Officer informed us that vehicle was belching white smoke.  

Since then, two start ups, white smoke both times.  Temps here are in 80s.  

Not many options with dealership as two-day return period has past.  I bought mechanical breakdown coverage from my credit union.  Obviously should cover, but issue I foresee is insurer arguing this was pre-existing issue.

Questions:

(1) anyone dealt with similar issue?

(2) are head gasket and/or cracked cylinder likely culprit?

(3) any suggestions for how to handle (other than having my local indy guy repair)

(4) this is VERY unusual for this vehicle at this age and mileage.  Any value in reaching out to Lexus - even knowing this vehicle is past PT warranty?

Thanks for help.  TG

[ttg7ya]

Additional info - no MILs on dash yet.  Opened engine and flipped cover up one hour after last cold start (very brief run time) and still hot to touch.