Roll resistances are different between them
Braking will be different between them
Roll-over of the side walls will be different between them
Slip angle will be different between them (this is seldom understood
and less how it affects tire handling...even longevity)
Of course weight carry rating will be different between them. You
have to air up the lower rated tire higher to match the carry capacity
of the higher rated tire in order to balance the load carrying
Then at what PSI each tire is at will factor *ALL* of the above
A bit better or less risk (on the good days out there) since no steer axle on
this trailer, but if there is a steer axle, then dangerous...
Dangerous...mainly on the day Mr Murphy crosses your path...either you have the
right stuff spot on or not. No time to go back to the store for proper stuff
Note that all things engineered and specifications/ratings/limits/etc written
are NOT for the good days out there...but for the worst case situation(s)...
Have no skin in the OP's situation, but am writing mainly for the
lurkers who might think this is a good/okay thing...it is NOT and a
risk management decision (AKA gambling) that Mr Murphy won't cross
your path...