Thoughts on gravel bike for 70.3?

Wanted to get some input and see if anyone here has done something similar!

I am doing a half Ironman (70.3) this summer and currently have two bikes:

• 2009 Trek 2.1 - Shallow aluminum rims with Conti GP5000 28 front/30 rear, SRAM Force 10 speed groupset, clip-on aero bars.
• 2020 Cannondale Topstone 1 - SRAM AXS 1x 48t 10-52t cassette, ENVE rims with 47mm tubeless tires

I like my position on the gravel bike and the AXS shifting. I am considering a set of EliteWheels (https://www.elite-wheels.com/product/time-trial-triathlon-wheels-tt-disc-brake-bundle/) with 30 or 32s on the gravel bike. I'd probably increase the front chainring to 52t as well.

How much would I be giving up vs riding the older road bike with clip-on bars? The AXS setup on the gravel bike would allow me to shift from the aero position with blips. The course is extremely flat.

Thanks for any input!