I have 3 purple HF lifting straps, with eyes on both ends. I think
that they are rated for 1 ton each. I will be lifting less than 1/3 of
one ton. I intend to use them for primary lifting (with chain as
backup).

Did your straps come with instructions? Particularly how to derate
them when used on an angle? For example you warp them around something
and put both ends on a hook. If the strap is at a 45 degree angle
it can only carry 1/2 the rated load.
cs