RafaLL92, I really do not understand how to do "professional recording" on a "less stable" storage. Does a professional will take the risk to lose 4 hours shooting ?

Concerning swap usage, I agree a flash memory lifetime will be shorten compared to standard storage. I comes from its internal behavior: copy/paste block content as it is not able to replace a single 1 bit to 0, and it is only able reset a full block to 0. There is also a block rotation thanks to address mapping: a free block is reset to 0, content is copied (bits 1 are set) and so on at next block write access.

As a consequence even if you think you only use a part of your microSD as swap, in fact all internal blocks of flash memory are used and that means the whole card life time shortens.