Is does the job to an extent. But if you plan to run the slack chain over the top beam, it’s not recommended.
My recommendation would be to go for a weight tensioning, as that has a constant force on the chain, independent where your sled is on the sheet.
Edit:
There are much nicer ideas for weight tensioning here in the Forum, but an ugly prove that it can be done with the roll-bearings from the kit is here: Poor man weight chain tensioning