Nice report.

What you are doing is obviously working so I don't want to suggest many adjustments, but I would urge not "letting the line back down." Keeping your rod tip up all the time (from the end of your forward cast to the start of your next back cast) will help you in three ways. First, you won't have to mend or grease your line to try to keep it floating (since it will not be on the water). Second, keeping the line in the air rather than on the water will improve your drifts by reducing drag (the greatest benefit of tenkara in my opinion) and third, it will greatly improve your hook-up ratio by keeping your line tighter and keeping it from being stuck in the surface tension.

Your drifts will be shorter, but I do believe the advantages will more than offset that.

You will find that to be hard to do with a 4.5 line. The lighter the line, the easer to keep it off the surface. Both of your rods will cast a 3.5 line nicely. I'd use it all the time (subject to wind, of course).

Do try fishing without an indicator. That will also keep your line tighter and make hook-ups easier. I think you'll find that hi-vis line is all the indicator you need.

You don't have to change anything. Fish any way you want. I think the above suggestions may help, though.