This probably won't happen in canon since we have Ultra Instinct and Ultra Ego but I still thought of the idea, Have Super Saiyan 4 Limit Breaker be the natural version of what happens when you stack Super Saiyan 4 on top of Super Saiyan God like how Super Saiyan Blue is Super Saiyan God + regular Super Saiyan (hence why it looks like SSJ but with a different color and different aura) and then have Blue Super Saiyan 4 be the result of stacking Ikari(Broly's wrathful form) on top of Blue, resulting in a similar form to SSJ4LB/SSJGSSJ4 but weaker since SSJ Ikari is more comparable to Golden Oozaru than actual SSJ4 in terms of power but still incredibly strong
I got this idea since even though it's never been officially confirmed as far as I'm aware it is a popular headcanon held by many including myself that Super Saiyan 4 Limit Breaker is the Super Saiyan God version of SSJ4 given it's immense strength and similarities with the SSJGod forms, plus how it was formed even if it does resemble the full power ritual from GT also resembles the Super Saiyan God ritual from Super, also this way we don't need to introduce Blue Oozaru or something stupid like that, we'll probably only see either of these in the future in non-canon spin-off media like Divers or it's predecessor Heroes or maybe in something like a Xenoverse 3 if Bandai ever makes one but it's still an idea I had, a bit dumb but still
The Blue 4 render