As described, requires a little initiative from buyer on tight spaces.
Add a little of WD-40 when adjusting the bars to tight spaces won't hurt and will help glide easily.
Price within range of Walmart for similar product.
Fit tubes in one holder already screwed in the wall, fit tubes in second holder, then screw the holder in place after adjusting the bars: will make for an easy install, and perfect length fit. Make sure there is some pressure exercised on both walls by the assembly, will reduce or cancel any movement in place from narrower bars.
Tubes will become harder to adjust if tight space due to curvature creating more friction than straight ones, hence WD-40 to avoid any scratches or bars being stuck.
Electric Dual Induction Cooker Cooktop 1800W Countertop Double Burner Portable