I am searching for a smooth round bump tactile switch.
but most good tactile switch seem to have high peak force more than my liking. 
I come from using cherry mx brown (genuien one) that very light and so litte tactile. I try cherry mx black (I know it's linear) that already too heavy for me .

if I bought tactile switch with higher peak force and change the lower force spring , Does change spring of tactile switch to lower force impact the tactility ?
and Does it have any other effect?

Thank you

Zealios changed their slider for "Zealios V2", and they feel different now. Zealios (old and new) come in four spring weights.

Outemu purple is also like a lighter Cherry MX Clear.

Myself I like the weight of the regular MX Clear. The weighting and the force curve actually makes it easier to not bottom out.

Zealios are measured by bottom-out weight.

This graph measured of a Zealio purple V1 bottoms out at around 62-65 gf and the tactile peak is around 56 gf.
However, Zealio V1 are being discontinued in favour of Zealio V2, and I have not seen actual measurements of that yet. I have heard people say that the tactile even is higher up, and that would mean that it does not feel the same.

Anyway. I think that it is not the top force but the size of the area under the curve in the graph that determines how heavy it really feels. If a switch encourages you to not press too far, then you might not get too much of an area. But it depends greatly on your individual typing style.

ZealPC switch "weights" refer to the bottom-out force rather than the actuation force. Tactility is a feature of tactile switches arising from a concerted increase and release of pressure due to a bump or cam on the slider (as in mx brown or clear), the added resistance of a tactile leaf (as in  SKCM orange Alps), collapse of a rubber dome (as in Topre), or the buckling of a spring (as in IBM buckling spring switches).

If the switch is purely linear (as in mx red or SKCL green Alps), increasing the spring weight increases the resistance but there is no tactile event, so tactility does not increase.

As others have noted, increasing the spring weight in the same type of tactile switch decreases the perception of tactility, because the relative change in resistance is less.

Cherry mx clears feel more tactile and heavier than mx browns because the tactile bump is bigger and the spring weight is greater. In my own case, I prefer to bottom-out my keypresses. Because clears have a rather high bottom-out force of 95g or so, I find clears too heavy.

I've tried ZealPC Zilent v1 67g and find them just about right with respect to tactility and resistance although maybe a bit too light. I have not yet tried v2. My understanding is that v2 Zilents have a more pronounced tactile bump that occurs at the top of the keypress and that the spring resistances are the same as before in the four grades that are offered (62, 65, 67, and 78g).

The weaker the spring the higher tactile feeling. Comparison in terms of MX Clear and Zealio tactility:

Zealio V2 62g>65g>67g>78g>Cherry MX Clear>Zealio v1 62g>65g>67g>78g

MX Clear is more tactile than Zealio v1. They use the same sliders but zealio is a bit pre lubed, less scratchy and doesn't have progressive spring like MX Clear which all adds to less tactility.