Quality of factory could be an issue. Anyway yet to see a Tar.
@Johny_Baba if Insas is internally same to an Ak, then what is the issue in giving an insas type fire selector for Ak which is as easy as cutting butter when compared with manipulating that of Ak? (Ps:Compared with that of SLR insas fire selector is absolute shit though)
Mechanically speaking,No issues at all, in fact many Kalashnikov derivatives themselves have thumb-operated fire selector on them, internally they are somewhat different but core working principle is same.
First of all, Mikhail Kalashnikov himself was inspired from John Browning's Remington Automatic Rifle (or Model 8 Rifle) where a giant fire selector on its charging handle side also doubled as dust cover for that charging handle slot on its receiver when on 'Safe', same thing on AK.
Trigger mechanism on it, although was inspired from another American firearm = M1 Garand (In fact you'd be surprised to know that AK in its very core is nothing but reworked M1 Garand rifle).
Anyway,back to point,some examples of AK with thumb operated fire selectors on them,
Galil, this one is just standard AK fire selector coupled with a lever on other side to make it act like a thumb operated selector, so you get standard AK fire selector on one side and modular thumb operated one on other, so in this design if you move thumb selector it also moves that big one on other side and vice-versa.
Then there was Kbk. Wz. 88 Tantal i.e. polish 5.45x39mm variant of Kalashnikov which had unique thumb operated fire selector on its left side to be used with common right-handed operation (with 3 fire mods, "C" = full auto, "P" = semi-automatic and "S" = 3-round burst) and AK style safety on right side that can either be on "Safe" or on "Fire", so you put your rifle on safe using conventional AK selector and choose fire mode using thumb operated selector on other side.
After fall of the USSR and subsequently Warsaw Pact, poland switched to Beryl rifle which was practically 5.56x45mm variant of Tantal, so basically same as this.
So yeah, from a simple added piece of metal to a complex trigger group it indeed is possible, and having such thing (and eliminating that big paddle safety) has its own advantages-disadvantages etc but i think i'll cover it later due to lack of time for now.
