Hi worked with Speedify. My experiences
Free = a few GB (unreliable, useless)
User account 50$ a year = unlimited traffic, public server. Not reliable due to public server.
User Account + own server (900$ a year) = I used this combination for some productions. Due to the continued opex I decided to a capex solution and invested in an appliance.

With the paid own server there is big enjoyment using multiple ISPs at once in a bonded way. You might want to consider additional NICs or USB modems with SIM data plan costs if you want to make full usage of the unbreakable connection.

Alternatively you may want to look into SRT for a more reliable media transport. (I also successfully tested Simplify with SRT port forwarding) But SRT works even without any VPN.

I hope that helps