Have you used fractional SDRs?

Hi, founder of Atom here (https://atomgrants.com)

We've been doing a lot of founder led sales, cold calling has been a huge lever and were debating the idea of using a fractional SDR to ramp this up as an experiment. Our burn rate is low (just founder salaries). We have about $100k in the bank and are at around $100k ARR.

Does anyone have any advice on the efficacy of fractional SDRs vs bringing someone on full time? If you have used them effectively feel free to share their details.

Thanks

Tomer