If you are not willing to wait, take any paperwork you have to a lawyer. There is no standard sales contract - each dealer will have their own. I put down $2,500 three years ago, when it was first announced. This was always fully refundable. I put down 10% when Lotus informed the dealer that their allotment was open, and I was assigned a VIN number at that point, and it became non-refundable. Tariffs were announced after that, and I was sweating if the car would arrive before the tariffs kicked in, and it did; it was on the last boat that beat the deadline, but did take my sales contract to a lawyer in case, and it said they were selling me the car at a stated MSRP with an indicated amount, so if there were tariffs, they could not change the price. Others on this forum had verbage in their contracts that allowed for unforseen price changes. So it's a bit of a crap shoot.
As far as getting a stock car versus custom, there really are not many options. 6 cylinder manual or 4 is about the only one, though there are very few 4 cylinders selling. Then there is color. Boom, done. After that, everything is a minor color choice. Caliper color, stitching color, wheel design, custom floor mats, radio upgrade are all really trivial, and I have a hard time thinking that someone's enjoyment of the car would be impacted by not having the preferred color seat stitching. Only other one is sport or touring suspension. I chose sport, though did not drive them side by side, and if they secretly swapped in a touring suspension, I would never have known the difference.
Dust will settle on tariffs, either they get lowered, or MSRP goes up, and this all will be forgotten. Tariffs were 5%, if they go to 10%, that's only a 5% increase on the value of the car at customs, ie the price Lotus UK sells it to the importer, Lotus USA. You then have to add Lotus USA profit and the dealer profit before you get to MSRP, so the extra 5% is not on $100,000, but maybe on $80,000. So it's $4,000 extra. Lotus will not remove itself from the US market because of that - there is no one on this forum that bought an Emira at $ 100,000, but could not have afforded it at $ 104,000.
Personally, I think the Emira is undervalued. I also have a 911T which was $150,000 versus the Emira at $100,000. The Emira looks better, is more fun to drive, and I have to think a Toyota engine is more reliable than the Porsche engine, so I think it compares favorably. Sure the info-tainment system sucks, the brakes are slightly grabby, I hate the Emira key fob, they went through year 1 struggles with bugs, and the dealer is 90 minutes away .... but that isn't enough to justify a $ 50,000 discount versus Porsche. Emira is a bargain in my mind.
