[Help please/​Updated] Best EA use of $250,000AUD/​$190,000 USD for metascience?

[Cross-posted on the SSC subreddit] [Cross-posted on OnScienceAndAcademia Forum]
UPDATE: I posted something similar 18 months ago, but am reposting due to some updated details and the fact that the money is now in hand.

SUMMARY: Need to donate $250,000AUD/​190,000USD to “improve science” in about six months, would appreciate advice on where to put the money.

An elderly relative of mine has sold a property and wants to donate a substantial amount of money ($250,000 AUD = $190,000 USD) to “improve science”, by which they mean metascientific efforts that industry or academia probably would be reticent to fund otherwise. Examples would be things like Registered Reports, efforts to ameliorate the replicability crisis, altering publishing incentives, etc. The money is available in 3 months and ideally would be donated within six months.

They are aware of my interests in Effective Altruism and my training as a scientist and thus want me to take care of it entirely. However, I am very junior and have little experience applying for grants let alone allocating money. Any recommendations for how I should go about most efficiently getting this money to improve science? Bonus points for doing it in a manner that would be tax-deductible in Australia (edit: international also ok).

Particularly good recommendations are likely to have a substantial impact on how this money gets allocated, so if you think you have a good idea I’d very much appreciate it. I can’t just give the money to AMF or the EA Funds, it has to be at least indirectly allocated to basic science or meta-science. I’m not sure who to ask – I’d speak to my PI, but it seems extremely awkward to go “hey, so I have this big potential source of funding that I can influence but it’s not for us, any advice on how to give it away to others?” I’d be happy to direct the money to be thrown into a bigger pile if there’s another group I haven’t heard of that either solely funds improving science or will let me allocate the money to that end.

Thanks to everyone who provided some suggestions last time I posted, including on basic science opportunities back when I was considering a slightly larger remit. Some suggestions from the last time I asked this question:

Thanks in advance!