its not exactly supported, but here's a hint to get you started if you were up for experimenting.
Edit
ap_ss_user_style_username.less and wrap the
<xf:foreach> loop like this:
Code:
[data-template="member_view"] {
<xf:foreach loop="$apSsUsernameStyle" key="$userId" value="$usernameStyle" if="$apSsUsernameStyle">
.ap-ss-usernameStyle--{$userId}
{
<xf:if is="in_array('bold', $usernameStyle.text_style)">
font-weight: bold;
</xf:if>
<xf:if is="in_array('italic', $usernameStyle.text_style)">
font-style: italic;
</xf:if>
<xf:if is="in_array('underline', $usernameStyle.text_style)">
text-decoration: underline;
</xf:if>
<xf:if is="in_array('strike', $usernameStyle.text_style)">
text-decoration: line-through;
</xf:if>
<xf:if is="$usernameStyle.color is not empty">
<xf:set var="$color" value="{$usernameStyle.color}" />
<xf:if is="$usernameStyle.color_type == 0 && $color.0 is not empty">
color: {$color.0};
</xf:if>
<xf:if is="$usernameStyle.font is not empty">
font-family: '{$usernameStyle.font}';
</xf:if>
</xf:if>
<xf:if is="$usernameStyle.glow is not empty">
<xf:set var="$glow" value="{$usernameStyle.glow.0}" />
<xf:if is="$usernameStyle.glow_strength == 1">
text-shadow: 0px 0px 8px {$glow};
<xf:elseif is="$usernameStyle.glow_strength == 2" />
text-shadow: 0 0 2px {$glow}, 0 0 2px {$glow}, 0 0 4px {$glow}, 0 0 6px {$glow};
<xf:elseif is="$usernameStyle.glow_strength == 3" />
text-shadow: 0 0 2px {$glow}, 0 0 4px {$glow}, 0 0 6px {$glow}, 0 0 8px {$glow}, 0 0 10px {$glow};
<xf:elseif is="$usernameStyle.glow_strength == 4" />
animation: ap-ss-animatedUsernameGlow--{$userId} 1s ease-in-out infinite alternate;
<xf:elseif is="$usernameStyle.glow_strength == 5" />
text-shadow: {$glow};
</xf:if>
</xf:if>
}
</xf:foreach>
}
This will restrict basic sub-style types like color, bold/italic/underline, glows to only apply on the user profile.
Other sub-style types like sparkles & inner-text animations will not be affected by this change, but you might be able to fully restrict all the sub-styles to profiles by making a similar change in these templates:
ap_ss_user_style_text.less for Inner-Text animations / color gradients
ap_ss_asset_sparkle.less for Sparkles
ap_ss_asset_font.less for Fonts