I really appreciate these suggestions. We're a fully bootstrapped ~20 person, $5M+ ARR company in the DevOps space. We're growing quickly and often wonder what an extra $1.5 - $3M could mean for us, but don't want the overhead associated with a traditional investor, nor to invest the time in raising. We get emails from 3 - 4 VCs per week, but never any alternative funding options like the ones you listed. CalmFund in particular could be worth exploring. I wish this space ("Tech Mittelstands"?) were better established.
You might be interested in TinySeed's Syndicate offering — we started this for companies who are beyond the needs of the accelerator but would benefit from raising money (for instance, to deploy on new initiatives, or to take money off the table as a founder, or to buy another business, etc.): https://tinyseed.com/syndicate-founders
