.It can't be set to 2tp per second. You set the # of seconds per 1 tp, not the number of TP per second. You can't put it at 0.5 sec / tp, lowest it goes is 1 or 0 (which is not a viable option as I described).
There are some barriers and frames that regen tp actually. Barriers there is Regenerate Gear Adv (restores 5% hp+tp on block, 92-97evp, no resists) and Regenerate Gear BP (restores 2% hp+tp on block, 181evp, 15 all resists), though those really aren't too useful in Ultimate difficulty as blocking is difficult to do (and the lesser "Regenerate Gear" is weaker than both and only hp); they can be quite effective in normal-vhard though, quickly filling up all hp and tp in a few seconds. Red Ring also regenerates hp and tp over time while equipped. As for frames, Spirit Garment and Spirit Cuirass restore TP (they have counterpart Revival Garment/Cuirass that do hp too), and Aura Field drains tp over time. There are also some select weapons that have regeneration on them, such as Madam's Umbrella (1 tp per 4 seconds), and s-ranks have the option to add it as a c-rank special, (though idk why you would). Glide Divine and Glide Divine v00 also have the special effect of getting a unique 'use' option after 10 minutes of being equipped which reduces hp to 1 and restores all tp.
Honestly there, there is one item in the game that is greater than any tp steal/regenerate weapons, tp regeneration units, tp regenerating frames, or tp regenerating barriers. It can completely restore any and all tp missing from a character instantaneously with no animation and no menuing, with no ill effects or prerequisites like glide does. These items may have faded into legend, but I assure you they are no myth; perhaps one day you might obtain the fabled Trifluid for yourself.