Question1: I have a good quality Mind Impulse Unit and a logis implant. When I activate the logis implant as reaction to get the WS/BS bonus, Do I get the +10 on the tech use roll from the MIU? I think the question here is does the logis implant qualify as "technological device capable of miu linking". In this scenario the MIU helps to get an immediate +10 BS because I am shooting with a gun capable of MIU linking, but I would get 10pct more change of activating a logis implant that will give me another +10 BS, that seems pretty strong and perhaps not as intended ?

L ogis I mplant (RT p. 101)

The Explorer may use analytical circuits to calculate trajectory

and reactions to a preternatural extent. His ability to read

possible outcomes lets him anticipate the movement of his

opponents. By using his Reaction for the Round, the character

may make a Tech-Use Test to make use of this Talent. He gains

a +10 bonus to all Weapon Skill and Ballistic Skill Tests until

the end of his next Turn. The Explorer must pass a Toughness

Test when he uses this ability or gain a level of Fatigue.

M ind I mpulse U nit (MIU) (RT 150-151)

These devices, also known as sense-links, allow the owner to

directly interface with a machine or technological device. MIUs see

widespread use among the Adeptus Mechanicus who regard them

as objects of divine communion. A basic MIU implant involves

a single spinal or cortex connector, while advanced variants

include wrist connector probes—and possibly mechadendrite

connectors—in addition to the spinal plug.

Common models impose no modifiers to machine spirit

communication and add a +10 bonus to Tech-Use, Pilot, or Drive

Tests used in conjunction with devices capable of MIU linking .

Poor MIU systems require a successful Willpower Test to use

and impose a –10 penalty to interact with machine spirits.

Good models grant a +10 bonus to communicate with machine

spirits, and for Tech-Use, Pilot, Drive, Logic, Inquiry, and Ballistic

Skill Tests when interfaced with MIU systems . In addition, an

MIU gives the user the ability to experience the senses of any

familiars he controls (such as a servo-skull or grapplehawk, see

page 375) as if he were present.

Question2: Do you have to make the toughness test regardless on whether the activation of the logis implant was successful or only if the activation of the logis implant was successful.

My answer is Yes you can Logis Implant with a MIU weapon.

and for #2. I would say you would have to roll for that toughness even if the if the implant didn't "work" as you were still trying to make it work

That would make the logic implant even less useful man.

Thanks for your insights

Well, Tech-priests have cheap Toughness advances, and can get the ElectrIcal Succour talent to remove Fatigue anyway.

Electrical succor doesn't do you a lot of good in combat, it takes a minute to activate...

If my GM lets me, I will try go electro priest way in the long way, like level by level 4 if we play that long and I survive that long... Activate logis implant (my agility is so bad I will never get to dodge decently anyway), go frenzy, ignore fatigue modifiers if I fail that Toughness test, I have 62 toughness now after spending my first char increase on that, by level I will get that machinator array another two stat increase on Toughness and if frenzy is allowed, toughness 92 and slightly more strength (with unnatural strength), over a 100 strength if I can get I can get the smaller power armour and slice things up with mono groxwhip that sends electric shocks for the parrying kind or a nice fat thunder hammer to hit those big foes, my agility is peanuts so I will be last, Id like in the end also to get unnatural intelligence and combat formation so my friends should have drained the reaction of the targets...