If grenades weren’t so terrible in Horde in Gears 5, I would have considered using the grenade capacity on Demo. Gambit, no, unless it was Overload and easy to plant some grenades in spawns. Escape, only extra grenades. You almost never need to plant more than two of them.
The only remotely useful grenade imo is shocks after wave 10, having used them to some effect with Slugger as I leveled it on Jingle Juvies(especially during the Scion waves as it was both damaging them to at least some degree and preventing them from shooting everyone up), throwing a whole bunch of them around. Incendiaries are more limitedly effective against bigger enemies such as Wardens and bosses. And even then, for the shock grenades I would find their utility limited because apparently every single Drone enemy ever has to go down every single time.
Fun fact, I also never really liked having extra grenade plants outside of speedruns in Gears 4 either because it seemed redundant and not particularly effective as they often just got triggered by some dumb Juvie or Tracker rushing ahead of everything else around. Throwing them was more interesting as well.