Hi Luis,
I would guess you're using the "Raw Data" option from Data Preview, right? If so, avoid that as much as you can, specially in models that will have lots of output attributes/measures. "Raw Data" basically goes 'all-in' and generates a query with *all* available attributes/measures possible.
That's clearly unwanted and indeed will generate lots of unecessary materialization. BSEG alone costs a lot to materialize completely (huge amount of columns there). That summed up with forced materializations with unions will be a memory/time killer as you can see (~200s and 283GB).
Other than that sharing the plv file might give us a better clue of what could be happening.
BRs,
Lucas de Oliveira