It's still pretty early beta and a bit buggy. I have 38k sats that got stuck using cashu.me with minibits mint. "Proofs Pending Error" I was going to reach out to minibits but figured I'd consider it a donation to their project instead. I've been testing the nostr:nprofile1qqstxwlea9ah3u6kjjszu6a7lrnhqkfh8eptp2z6v0e9558tlkkl2rgpz4mhxue69uhhyetvv9ujuerpd46hxtnfduhsz9mhwden5te0wfjkccte9ec8y6tdv9kzumn9wshszxnhwden5te0wfjkccte9ekkjmnfvf5hguewvdshx6p07xr4s5 wallet and only have had one transaction go missing (using their lightning address feature). The devs are still trying to troubleshoot it. I find the minibits team very responsive. I know it's still early beta so I try testing as many noob scenarios as I can think of. Hopefully I find a big and can replicate it for the team to troubleshoot. I agree sats shouldn't be lost but I don't recommend these projects to newly orange pilled users.
I haven't had custodians rug me but bugs causing loses I have seen. But again this is for testing not ready for primetime in my opinion.