I use the ANT-54 on mine with no issues at all. These have thread protection all the way down the length of the center pin. This is a MAJOR consideration, as not all SMA-F antennas will fully protect the pin (and lead to all kinds of strange behavior due to RF ingress).
It's not meant to be an improvement, it's made to take up less space.
I use the 868 as a backup to my 7550e on my hotspot, and my county public safety is all on VHF analog repeaters. It works perfectly for what it's intended for (basically, a nightstand radio & fairly unobtrusive to the eye with the smaller antenna).
Caution - Be aware that the Anytone radio is likely to be much more susceptible to low-level or out-of-band interference when connected to an external antenna. You might want to borrow an antenna and try it before committing to a purchase.