The main thing is the Endura is keeping me off the cigs. It
That is all that really matters.
After all, fags taste shit but we smoked them for years or decades.
I suspect the lack of taste has little to do with your kit, but now you are an ex smoker, you could do with a backup setup and a backup for the backup. Then you could have three flavours on the go. Switching flavours regularily should help.
Given you are not totally satisfied with the T18 it might well be worth trying another device as your backup.
I am not the right person to give that advice but if you posted some thoughts on what you think of the T18 that might generate some sugestions.
Is it the right size? Are you happy with the draw/airflow or could it be looser or tighter. Do you like the simplicity or would you like more control over power settings (probably a larger device.) ?
You are doing well. Four weeks without fags is all that matters. It only gets easier the longer you go. Keep it up. Look into another setup. Once you have two different devices to compare, you can develop ideas about what you prefer before buying your third. By then you will be finding out if some aspects of these devices help you with flavour.
Nobody has suggested stock coil alternatives to the T18.
Even if they do not improve flavour Steve needs a backup so some suggestions might be useful.