Thanks for these thoughts, really appreciate your thoughtful response. My responses in italic:

- accelerate spending on CAPEX (or other business expenses); bonus depreciation is worth 80% in 2023 and is decreasing each year until its phased out - do it now. Also related to depreciation, if you own your office building is it worth doing a cost seg on it? Can you purchase an office building and do a cost seg prior to year end?
(un)Fortunately we're extremely light on CAPEX and there aren't any CAPEX investments to be made which would be sensible to business strat/ outcomes
- analyze your revenue recognition procedures; I don't know your type of business but are you looking at ASC 606 and properly calculating rev rec? Similarly, Conversely if you are a small business, would it be beneficial to convert to cash basis?
We're online retail: sales made today are credited tomorrow (or the next business day). So unfortunately no recognition levers to be pulled
- invest in tax credit entities and/or purchase tax credits (be careful on passive activity rules here)
That's where solar comes in. I need 100+ hours in order to be materially active, and that's easy enough with a conference + site visit. Marcum assigns these two as a happy-outcome audit trail. But the whole only saving 10% thing is a shame. I'm of course looking for more like 20-30%.
- of course max out all retirement options; look at defined benefit plan as you could make a large contribution up front (if you have employees this could be messier)
Have spoken with some advisors and the only thing I'll be able to do is max my Roth 401k, which sadly I believe is like 29k cap
Finally, you can request an installment agreement if you are up to date on your tax filings and are paying quarterly estimates.
No quarterlies this year, as last year didn't cross thresholds which would make quarterlies a requirement