Well I certainly would be happy about more strategems. And in fact the spirit of how you're suggesting them (as a conversion or trade-off of less-used benefits) appeals to my tactical mage side.

First, I worry about the numbers you suggested, so maybe they just need a little tweaking. I'm imagining areas where I can full-time Embrava (Abyssea, Besieged, half-time in Nyzule) and don't necessarily have to staff swap. That would be up to 7 TP per tick regain that we could could store every 15-30 seconds. I'm not going to work out the exact math but I think if you could recover a strat for every 100 TP, you'd essentially double our available stratagems under Embrava. Maybe I could chalk that up to a SCH-specific benefit allowed for Embrava though, so I'm not sure it's all that bad.

I'm also imagining this creating some unfamiliar desire to melee on mobs where I can safely get close, just to gain TP for strategem conversion. So for example if I'm playing the LA SCH (and not gaining TP through Occult Acumen) and can live with just an Arka IV equipped long-term, I'd be tempted to jump into the fray to fill my TP up for this ability. Not saying that would be horrible for everyone, but I'm not sure at this stage I want to think about "idling" in melee accuracy gear on SCH.