Lastly a horrendously complex solution. You could implement “Insulin Stacking” and a computer; this would require some mug sorry “patient” to test such a system.
Insulin stacking is actually fairly easy and safe if you've got cgm and learn over time from what it's telling you.
I know not everyone has cgm but times are changing - it's becoming increasingly common place, especially with scripting of libre slowly becoming more liberal in some parts of the country.
Stephen Ponder's book Sugar Surfing, and William Lee Dubois's Beyond Fingersticks both cover pre-bolusing and insulin stacking in depth.
Here's an example from mines today, see pic below..
Pre-bolused 7u to get some in stream about 20 mins before a Chinese buffet at 12:40, from past experience reckoned another 4u on top would cover it, put it down as 70g, but buffets are always a bit of guesswork, I reckon after seeing the line it was likely nearer 90, but the accuracy of the carb count didn't really matter that much because I knew that the stacked 11u was roughly in the ballpark for that meal and I could simply watch to see how it played out and adjust as necessary.
So, by about 2pm, I'm starting to get clues from the blue dots and also the purple estimated prediction dots, the remaining IOB count and green insulin decline line that it was starting to trend up unduly and the iob wouldn't pin it, so stacked another 3u in at 14:20 after the trend was confirmed, so pinned it to about 7.6 before a decline to 6.
Yes, stacking can require a few more injections than normal, but I find injections to be as much discomfort as using a lipsalve, and they're not always needed: if you eat a similar meal later, you'll have the past knowledge of what worked for that meal stored away, so there's an improved chance of nailing it with one shot the next time.
There's a fair number of us doing Sugar Surfing and stacking now. Knowing IOB and seeing how bg is trending makes it remarkably risk free.
It does take a bit more glancing at my phone/watch than other methods, but I'm willing to do that as putting a little more effort into staying in range makes me more content with life.
The graph can look quite complex but, like anything new, after a while using it, you start to see much more in it and can make much more informed calls on whether to stack or not.