Preforming contracts for multiple files at once?

Greetings. We are evaluating (especially in terms of performance) the use of Filecoin as part of the communication infrastructure of an IoT system we are developing for research purposes. Reading the documentation it seems that the negotiations are typically (or always?) done on a per-file basis, so the upload time is coupled with the contract stipulation.

Systems from competitors (namely Sia) offer a way to use contracts to “preallocate” a certain amount of space which will later be filled by actual files, allowing to decouple contract stipulation and upload (which in our usecase is important to reduce upload latency: imagine having a node which will produce during its lifetime a certain amount of data, made available to other nodes as soon as it is produced, by uploading smaller files. If a single contract is formed for the entire “chunk”, performance should be sensibly better, compared to forming one contract for each file). Is this possible in Filecoin as well?

Thank you.

PS: We already tested our infrastructure using “pure” IPFS, but Filecoin’s additional features (especially the Proof-of-Spacetime) are very interesting for our research.