Cheap 'biners (or mosquetons as they are called on Fraaannch) are spit out of Asian manufacturing plants by the thousands. Some are reasonably strong and will support the weight applied to suspension lines. Others, maybe in the same lot, will fail at those weights. Just because one holds does not mean that others will.
OTOH, climbing and life-safety rated 'biners have traceable manufacturing documentation. They are manufactured in controlled conditions with impeccable QC. That is why they have the UIAA stamp on the body - the design and construction has passed independant testing protocols.
Some are even individually tested by the manufacturer. INDIVIDUALLY! Expect to pay more for such fine equipment. And sleep secure that you will not be let down in the middle of the night.
Use the key ring cheapies anywhere you want, but for suspension lines pay $12.00 - $15.00 for a pair of quality clips.
End of sermon.