If you keep discharging battery through your gizmo, you shorten it's life.
Yose batteries have poor size to capacity ratio. My Yose 36V 15Ah battery is the same size as 48V 17,5Ah.
Sag is also a problem. But I know what you mean. I don't like huge batteries either.
Technically your throttle is illegal, but also so is your trike. Best way to make your trike and throttle legal is to go through single vehicle approval process. Cost of £55 as far as I remember.
https://www.pedelecs.co.uk/forum/threads/pedelec-law-the-details.37594/
If you are on a budget, check
https://www.pswpower.com/?DIST=RkVFFFw%3D
PSW is my favorite supplier. I am talking about components used to convert bikes, not ready made e-bikes. Personally I find e-bikes available on the market overpriced and not a good value for money.
Woosh would be another...
I like Ananda, but they sell OEM products only as far as I am aware, so not really easy to repair.
Bafang offers great products and good amount of spare parts. I wouldn't call their products cheap.
That is a good thinking... hmmm... Bike is worth £1000, so If I get it, I can always sell it to somebody for £500. This way we will both benefit from this deal. Sharing is caring :)
Oh man! I don't have space for more bikes. Why are you tempting me?
On second thought it would be selfish of me to ask for yet another bike while I have so many. I guess I will step back and just feel sad and left out while everybody else will get a new bike :(