I'm not aware of any bad effects of using room temperature clearing
baths after a "hot bath" developer.
We are warned against sudden temperature extremes with silver materials
because of the danger of reticulation, which happens in the gelatin.
Since there's no gelatin in platinum paper, there shouldn't be any
problem going from a 100 degree developer to a 70 degree clearing bath,
and I've never seen any.
BTW, I'd strongly recommend a water rinse between developer and first
clearing bath, whether you work in trays or a Jobo. Clearing will
proceed better, and your clearing baths will last _much_ longer. I do
the rinse at about 80 degrees, whatever temperature the print may have
been developed at.
---Carl