I don't recall DESQview to be all that crashy. I was aware of a number multi-line BBSes that used it (just in the 416). Some BBS software called out its use specifically:
* https://www.synchro.net/docs/multnode_config.html
* http://software.bbsdocumentary.com/IBM/DOS/OMEGA/
Also, a comment from someone whose uncle co-founded the company Quarterdeck:
* https://news.ycombinator.com/item?id=29396561#unv_29400530
Also, also, if anyone wants to simulate the old-school DESQview experience, perhaps try out "twin":
* https://opensource.com/article/20/1/multiple-consoles-twin