> Im torn between just biting the bullet on the official Canon BG-R10 and the Neewer knockoff. Honestly, grab the Neewer Vertical Battery Grip for R5 R6 R5C! I have used it for tons of shoots and it has been absolutely fantastic for the price!! Never noticed any shutter lag tbh. If you are worried about rain, just grab a cheap cover and use the $270 you saved on extra Canon LP-E6NH High Capacity Lithium-Ion Battery packs instead. You will love having that extra cash!!

tl;dr: Vello BG-C18 Battery Grip for Canon EOS R5 R5 C R6 R6 II is the reliable middle ground. I'm very satisfied with the Vello since it handles the high voltage draw for 20fps bursts without issues. Shutter response is instant and battery data displays perfectly on the R5 screen. It works well and feels way more rigid than other cheap options. Its basically the only non-OEM one I trust for pro work.

> if it rains at the venue I'm screwed. Saw this earlier but just now getting around to replying. That weather sealing worry is totally legit, especially for a paid gig in the city where you cant always predict the coverage. Honestly, I've been super satisfied with my third-party setup for a while now and had zero complaints, but I have a couple questions before you drop the cash. First, are you planning to use the official Canon LP-E6NH batteries or are you looking to save on the cells too? Also, whats your heaviest lens you'll be using for the ceremony? If you're rocking something chunky like the Canon RF 70-200mm f/2.8L IS USM, the slight flex in the cheaper grips might actually annoy you more than the price of the OEM one would. Just trying to see if you need the structural rigidity or just the extra juice...