I did another hour on the trainer this evening.
I have moved the game controller up the stem using a Garmin mount held on by stretchy bands. That got it out of the way of my knees but it isn't held so securely now. It moved a couple of times while I was using it. I might try fixing the mount onto the stem with cable ties instead.
I started off in a bot-paced group ride but I was fiddling about with the game controller as I rode and accidentally turned away from the bunch at a junction, turning it into a solo free ride!

[PS I forgot that I had planned to try a virtual Cragg Vale climb. That will have to wait until another time.]
I got the fan remote control working again a couple of days ago by replacing its battery. Unfortunately, I forgot to switch the fan into standby mode for this ride so once again I had to dismount to turn the fan on mid-ride!
I have now discovered cruise control; I like it for free rides. I set it to 135 W to warm up after I had turned away from the bunch. Stupidly, I had not warmed up before joining them so it was good to ease off and then build back up.
After about 10 minutes I raised the cruising power to 150 W, and then in increments to 170 W. The buttons at the back of the controller nudge the cruise power up or down 1 watt at a time for single presses, but double pressing in quick succession changes it by 5 watts. I managed to get a step of 10 watts, which was probably by a triple press, but I didn't confirm that. I rode at 170 W for a while then gradually stepped up to 180 W. I maintained that for around 5 minutes then spent nearly 15 minutes warming down to around 130 W.
Cruise control wouldn't be much use for racing but for free rides it is more convenient than virtual gear changing. It is effectively a more flexible erg mode.
I tried virtual gear shifting with cruise control disabled but my attempt to improve the range of virtual gears in setup didn't feel like it was doing what I had wanted it to.
I had increased the number of gears to 32 and set the default gear to halfway through the range. I thought that TPV would make that a reasonable virtual ratio and give me a good range of ratios above and below.
What TPV actually seems to do is to make the reasonable gear ratio 'gear 0', 1/4 of the way through the range. The gears are displayed as -8 to +24 (actually 33 gears!). The negative gears are easier, for climbing; the positive gears are harder, for going fast.
This is overgeared for people like me! I need a much lower gear for climbing and don't need super-high gears.
I would have to turn trainer difficulty way down to race on any route with significant hills.
I might get in touch with TPV and suggest changes to how the virtual gear range can be user-configured.
What else...?
Oh, I am
still uncomfortable on the turbo bike. I am racking my brains trying to work out what the problem is. I need to sort it out because it is making even 1 hour very uncomfortable. I had thought of trying to do 2 hour virtual zone 2 rides over the winter, but no way until the comfort issue has been tackled.
Standing to ease the discomfort feels odd compared to standing up on real road rides. Another thing to look at.
2 steps forward, 1 step back, but I am making progress getting this set up the way I want it.