Unleashing a flood of instas at a low rank gives a MUCH greater reward than at a higher rank.  Because of this, we need to offset the added benefit with an added cost/work/sacrifice.  You sacrifice being able to do petties now for a much greater reward on a later account.  If we allowed people to toggle them on or off, then you remove that sacrifice altogether, and thus, we would have to switch rewards a bit and dedicate quite a bit of time storing the various insta petties of when you earned them so that they can give the appropriate reduced rewards at the time you use them

I wouldn't be opposed to doing this, with 4 conditions: 

If you NEVER pause them... then things are 100% normal

If you PAUSE them, then these things now count towards all reserved instas at that time (so if you had 100, then these 100 are bound to the below rules, but if you earn 5 more after they are toggled back on, then you have 100 bound to the rules, and 5 that are not and are normal and can carry over/count towards gun and so on)

1) As long as they only count at the XP of the rank they were earned at, (Right now they are calculated at the rank they are claimed at, which can be a huge difference)
2) They wont count towards a gun
3) They do not count towards your next account.
4) That there was some kind of cap to how many you could use in one day so there is no surprise huge units that are off the radar without any real sacrifice.

The reason for the conditions is there are a lot of low level protections built in for safety/fairness of all players accounts. Its always hard to balance quality of life features when they sort of conflict with game mechanics that are necessary. I'm OK with this if you choose to sacrifice by not doing any petties/felonies on your past account to accomplish this, but, I think being able to choose to use them or not sort of side steps too many mechanics built in for the protection of everyone. The above 4 conditions (possibly more, those are just off the cuff) seem to satisfy that side of the agreement.