Thank you everyone for the awesome discussion and feedback. I'm still taking in all this information, but I think here is where I am at in terms of options (in no particular order):
I do have one final question - while looking at KBD67, many other boards came up - Tofu65, TADA68, GK64, THINK6.5, etc. etc. Is there a reason to select any of these other boards over the KBD67 when looking at it from the perspectives of budget (at least similar in price) and noise?
I think you've recognized that you have two good options.
One, you could get a Ducky with Silent Reds [or use your membrane keyboard] to tide you over while you work on a KBD67 project. [You could alternately work on a KBD75 or other design].
Two, you could go Topre.
I know that Topre is expensive and difficult to test before buying. But it's a really, really solid option for what you want.
I've typed on 45 gr silenced Topre, and it is pleasant enough. Topre is rubber dome, but what does that really mean? Feel-wise, it is tactile but without the 'interrupt' that you get in the MX 'tactile bump.' Instead, it is almost linear in its smoothness if you press it slowly, but the tactility is present the entire time. There is a resistance in the background until you bottom-out.
It's a mild tactility compared to heavier, non-silenced Topre. It should be easy enough to get used to.
I'm trying out an ABKO K935P right now. It's a Topre-like board. Unsilenced, but very deep 'raindrop' sound. Maybe I'll post a review in a few days.
So Topre is very much a solution for your needs, if it's silenced. It's expensive, but you only have to purchase once, and there's no modding involved unless you want to. IMHO 45 gr silenced Topre is very usable in an office, especially if you lube it.
WRT your question about other boards, the KBD67 is valued by many because it offers most of the features and quality of high-end 65% boards, but at a lower price. There are boards that are going to be finished a little nicer, more rounded corners, more uniform plate colour or something, I don't know, but it's going to cost a lot more. Diminishing returns. The KBD67 is offering serious quality for less money.
The other KBDFans 65% boards often cost less, but aren't as good. The TADA68 is good value, but has a worse layout than the KBD67 [arrow keys are in a separate cluster on KBD67] and probably doesn't have as many programming features IDK. The switches on the TADA68 face upside-down, which leads to a less consistent typing and sound experience when using Cherry profile. To be fair, the TADA68 has maybe the best-performing aluminum case options in its price range. So the TADA68 is like a budget, inferior KBD67. And I think it may be in the process of being discontinued.
The GK64 is also in a lower tier than the KBD67. The 64 is built alright, looks nice. It has RGB, I think. Hotswap. But the key staggering is non-standard. Probably better as a gaming keyboard.
I don't know much about the Tofu. People seem to use them in association with customization. Like they use a Tofu case, but a PCB from a different board. So it ends up as a hybrid.
KBDFans boards that are probably in a similar tier to the KBD67 are the KBD75 and upcoming Bella. The KBD75 is very solid, I've typed on a few. I honestly prefer it to the KBD67, but that's because I'm not big into 65%.