Does protective gear & e-collar & restraint make scared kitties become aggressive?

Dilemna. Cat stiff, scared, quiet. Wear protective gear. Next visit, cat is more scared. Ir don’t wear gear, no e-collar, light restraint, kitty might eventually relax…OR might bite & scratch groomer. WANT to use little to no restraint, BUT scratches and bites can do big damage. My dilemna. (C and C. Dsh tabby young adult)