Can you state what these problems are? I have voip.ms but haven't actually used it as my primary number for awhile. They have SMS (using their custom app) and VoiP using SIP. Its too bad native SIP support in android (google pixel) wasn't that great for me which is why i stopped using it
1. Numbers don't work for banks' snake oil auth, craigslist account signup, etc. Either silently fails or says the number cannot be used.
2. Calls (to an iPhone, at least) where the number isn't already in address book show up as "Spam Risk" rather than the phone number.
3. Have had some people unable to text a voip.ms number, eg from Comcast mobile.
I'm not trying to hate on them or anything. I'm a happy customer for what they are. I just think these are limitations of all consumer-facing libre-protocol VOIP services, that GVoice manages to sidestep due to Fi, but I'd love to be wrong.
FWIW I've found the Voip.ms Android SMS app a bit flaky.
I may have seen that thread, and it probably gave me the idea for my second option. Still, I've got to wonder about the relative hassle-insecurity of a cheap MVNO versus GVoice. Like sure Google has a bad rep, but at least they've got good common-case security properties. Whereas a lowest bidder MVNO is likely to have poor security to begin with, and poor customer service for cleaning up after the fact. It might still be worth it to try a GVoice number first for every service, then fall back to the mule. (although everpresent point against Google: they're better at exploiting surveillance data, in a way that an MVNO won't be)
"all of these phones" implies you have expanded to multiple mules? I presume for multiple accounts at the same service? Is there any indication that really works for eg making it so all your Google accounts don't get locked at once? Or are you doing it to undermine the use of phone numbers for cross-service surveillance association?
FWIW I haven't looked in a while, but the cheapest US consumer SIM I've found is H2O Wireless (on AT&T) at $10 per 3 months.