I highly encourage other founders to do the same. It doesn't require your company to be massively profitable with hundreds of employees to make a $20-30k annual commitment to supporting open source.
It's been established that this may be achievable for a small startup. However convincing key stakeholders that this would lead to an increase in a quarterly return may prove to be a unique challenge.
When you donate a sizable amount to an open source dependency, you get clout with the devs of that dependency, it's easier to rely on them for support if you need it. You can expect them to care more about the bug reports you send in vs. other people, etc.
In addition, you ensure that the project is healthy, less likely to have serious bugs and issues that could destroy the value of your firm, etc.
This is also why many open source developers sell support contracts or paid support in any shape or form.
Separate from a 'what will the shareholders think?' vantage point, this is a valuable question depending on your tax jurisdiction. In the UK, such sponsorships will be tax deductible only if you can answer this question in a satisfactory manner (or if the recipient is a registered charity, which is unlikely).
HNers often ask whether this is somehow dodgy, which it is not. Both of the tax agencies which care about my business give me virtually carte blanche to determine which products/services are necessary to keep the business running, subject to their standard regulations, and it is my considered judgment as a business owner that the software I use is necessary and that the amounts I pay are appropriate to the value received.
As long as you can show the directors aren’t benefiting indirectly from this then I think it’s unlikely to be an issue, especially if you’re using the libraries in question? HMRC don’t require you to prove that you’re running your business to maximise profit, just that you aren’t disguising director payments as expenses.
For example, if my company fancied donating £1000 a month to the curl project because we think it's a fantastic tool worth supporting (it is!) but we only use it in a handful of scripts, HMRC might give us some grief if it came up in an inspection. I dare say given the expected technical knowledge of the average tax inspector that a typical HN reader could prevail in such a challenge ;-)
The lead of the OP is something to follow, though!
Another great example of the overall effect described in the classic https://slatestarcodex.com/2014/07/30/meditations-on-moloch/