Carrying a couple 870 12ga shotguns in a section seems more relevant than DMR rifles now days - especially if we're going to be putting 6x or 10x optics on rifles.
Horrible take
Shotguns are exceedingly limited by ammo capacity, which makes them basically fucking useless in combat.
On the GL, I think the Grenadier is better suited by the M32A1 Multishot Grenade Launcher, (with a short carbine also issued). Then a M230A1 stand alone as an option for Squad/Section leaders for marking.
I do like a micro UAS option of the section/squad level. They are super small they can be controlled on a phone that’s already on the Member and it’s just a tool toolbox aspect. There are also slightly larger 40mm launched systems that can be launched as needed to gain SA. They can be set to follow mode / so clearing a trench system they can indicate limit of exploration on lead elements for fire support direct visually.
Now on the DMR. I am a believer in the DMR at the Platoon level. I’m less and less a believer at the Squad/Section due to High Pressure 5.56mm becoming viable.
Based on your delivery timeframe, I don’t think your new rifle will be high pressure compatible which I think is colossally stupid so com is running high car down here ( high pressure, carbine,) later this year. Having shot a high pressure option from one company I was hitting Larue’s out to 780m very easy with an EoTech and 3x mag from a 11.5” barrel.
There’s definitely still some fleas both on the ammo and the weapon side to work out on my pressure. But realistically what more you want at the squad/ section level? Especially when HighPressure LMG’s are included.