There are numerous switch-mode regulator modules on AliExpress and Banggood, even on Amazon Marketplace (but they still usually ship from China). Many are variable (making them more general purpose), but there are fixed 5V ones.I thought that
LM 1086 IT5,0or
LM 1084 IT5,0are fixed LDO 5V regulators.
TI datasheet: 10 uF tantalum on output and 10 uF on input.
I would prefer a tiny insulated board with all parts - do you know any?