There’s that Bruce Lee story of him holding an 8lb steel ball for hours, alternating hands, in a front raise hold.
The front raise hold isn’t given the credit it’s due.
One light dumbbell kept bedside (I have a pair of 10s in my bedroom) easily becomes a front raise hold as a shoulder feeder workout and results in fairly quick gains.
Even :60 is great, meditative, you breath in and out deep, and you find it’s not just the shoulders firing, like horse stance you feel your legs, glutes firing, and the grip is worked.
Lengths of time see the entire body pulling that dumbbell up.