I would invest in something to protect the underside of the spray foam insulation from insect and/or rodent infestation. Provided the insulation thickness is adequate, I wouldn't do anything to limit ventilation of the space between the bottom of the joists and grade. If you want to improve the aesthetics, I suggest installing treated wood lattice in lieu of the metal panels you are considering.

" . . . the minimally recommended area of screened vents to allow moisture to escape from the enclosed area under the house."

Consider enclosing the space under the house (above and beyond code requirements) and heat, cool, and ventilate the space as if it is another room in the house.

Metal panels corrode over time.

Vents that let moist air out usually let moist air in also.

A WRB (e.g. Tyvek, Typar) is better than the polyethylene sheet on these skirt walls.

The rebar stakes and wood sitting on the ground (even with the plastic under) is not the best scenario, but I don't know how far you want to take it.

Metal panels will work with your flush T1-11 if you use mobile home prefab skirting so it limits the corrugation depth and has a nice transition cap (and bottom track).

The passive ventilation is fine for how your crawl space is set up. Going unvented would require a bit more, and again don't know your context.

Are those blocks core filled and rebarred? Is there a foundation poured below the frost line with the rebar extending into the block? There appear to be zero brackets holding the home to the block. You have uplift forces here that you need to engineer against or that shed is going to come right off of those blocks in a heavy thunderstorm. Every single thing needs to be firmly and permanently attached to each other from the earth to the roof sheathing.

It is not apparent in the previous photos, but there are 18 tie down anchors embedded in the concrete footings which support the block piers. Both vertical and diagonal tie down straps run from the anchors up to the 4x6 main girders. The girders are fastened to the joists with simpson hold down clips. At each wall stud location there are 4 hurricane anchors - a) from sole plate to joist frame, b) from bottom of stud to sole plate, c) from top of stud to cap plate and d) from cap plate to rafter.

@Delta Systems - Forgot to direct previous comment to you.

That closed cell insulation doesn't look right, it shouldn't look like it has dripped down the joists. You might take a core sample to make sure the mix was right on it.