I apologize if this was asked and answered, I looked but did not find 
Do we have the ability to interact with groups over SMS such as for a group of coworkers?
If yes what is the maximum capacity?
I am thinking of a chat group for my team of eighteen individuals. We had been using an xmpp solution but groups on that protocol max out at less than that, ten participants if memory serves.
Hello Trifle1767,
At the moment SMS/MMS capabiities does not include group interaction, currently only a traditional usage is offered , for more information, please check https://wiki.voip.ms/article/SMS
Trifle. further to Willliamās reply, your colleagues with conventional SMS can include you in their group SMS. You will receive the SMS to the group. However, you can either respond to only the sender, or for for every reply you send to the group, you have to add all the recipients in the field āPlease select or type a contact numberā. Note, your outgoing SMS are individual messages to those in the recipient list, if your colleagues reply, it is only to you.
At the moment there is no information in this regard, ill highly recommend to add this as a feature request through https://www.voip.ms/m/features.php
Just did so. 
I am also having this issue and made a request.
I was added to a group text chain for work colleagues (who I also personally like) and when I reply to them as a group, adding all their numbers in the text portal even, I got a reply of:
āWhy arenāt you responding to the group text chat?ā So itās sending them out to them individually, and Iām getting messages individually.
Which means if I reply honestly (āI usually donāt keep a regular cell number at all because I find them hard to deal with when getting spam calls etc and this lets me separate my contacts and delete numbers if needed and help reduce the likelihood of being hacked by compartmentalizing if thereās some sort of breach on a server somewhere because someone didnāt update their database code leading to a vulnerabilityā) they will be confused and annoyed.
If I lie āOh, I just donāt understand how group texts workā then I seem like a liar and an idiot.
For now Iām just not responding. Really, I would hope voip.ms would make this a much higher priority because other providers have this. I am considering porting at least 1 number out unless this is actively being looked into or worked on. Eventually Iāll have to say something, probably just saying my text messaging app is in beta and I usually use Apps and not texts.
Generally I am a big fan of voip.ms, however, because the prices are so affordable and the quality is reasonably good. Does anyone know if this is currently being worked on or if they are trying to improve this at all?