Some in my reading list, sorted by how relevant the SF is; Knights & Magic - Mecha Forty Millenniums of Cultivation - Cultivation The Experimental Log of the Crazy Lich - Mecha? Implied to come soon. I Said Make My Abilities Average! - More like fantasy in SF tho~ Kumo Desu ga, Nani ka? - Seems like the elves have some tech.
Knights and Magic - MC is into robotics Magic Robot Aluminare - mecha in sorcery and magic My House Is a Magic Power Spot ~Just by Living There I Become the Strongest in the World~ - not really mecha but MC has apple trees he can equip like a mecha suit After Reincarnating Into This Game World I Seemed to Have Taken Over the Control of Status - sci-fi-ish Modern Weapons Cheat in Another World - summon military weapons in a world of magic and dragons Science Shall Prevail Over Magic - MC has hi-tech gadgets, transported to a world of magic Magi Craft Meister - mc has skills in robotics in a world with magic
Tempest of the Stellar War - Mecha and unique training methods Battle Frenzy - no mecha but set in a futuristic world along with people training their soul power Star Rank Hunter - no robots but the mc gets caught by someone crazy and ends up with computer chips in his body (does that count as a cyborg?).