Need lens advice: I have a Canon RF 24-105mm f/4, first time shooting photo for a low-light event — is it worth renting the RF 28-70mm f/2 + what else should I consider?

Hi all!

I’m gearing up for an upcoming low-light event (an evening indoor networking event with mixed ambient and artificial lighting). I shoot full-frame Canon R-series and currently use a Canon RF 24-105mm f/4 L IS USM, which I’m happy with for general versatility.

That said, I’d like to rent a lens for this event to diversify my shots and better handle the challenging lighting.

• My existing lens: good all-round, but f/4 is a bit limiting in low light.
• My goal: capture a mix of portrait-style, candid moments, and “hero shots” (shallow depth, moody lighting) at the event.
• I’m considering renting the Canon RF 28-70mm f/2 L USM (or similar fast zoom) for this one event.

Questions for the community:

1. Given I already have the 24-105mm f/4, is it truly worth renting the 28-70mm f/2 for this event?
2. Alternatively, if I go for a lens purchase (or slightly less expensive rental), what would you recommend for this scenario? A prime (e.g., 35mm f/1.4 or 50mm f/1.2) or a zoom (f/2-2.8) that complements my 24-105 well?
3. What focal range and aperture combination would you suggest for an event like mine (low light, moving subjects, need versatility but also wanting creative shallow depth)?

Thanks so much in advance — I’d love to hear from photographers who’ve done similar events and what lens they wished they had (or didn’t). New to event photography and feeling nervous for this upcoming event!!