eGPU Bottleneck and Viability

I have a Framework 13 AMD 7040 and I really like it. With a combination of a turbo clock speed of 4.9 GHz, 32 GB or more of DDR5 RAM, and Honeywell PTM it should be the have the performance of a decent gaming PC. However, as an laptop enthusiast, I naturally want to add an external GPU. How do I know which GPU to pick that won’t exceed transfer speeds of 40 Gb/s (the max capability of USB 4)? Are there any catches or performance hits for using an eGPU (assuming it is not bottlenecked by USB 4)? Let me know if there are other important factors I am not considering.